Abstract For a soil to be granulometrically stable, it must present low plasticity and a granulometric composition that conforms with the limits regulated by standards. This article presents a study of the clay fraction activity and plasticity of three laterites from the Triângulo Mineiro region, aiming to use them in a granulometrically stabilized base. The experimental phase contained the determination of liquidity limit, plastic limit, sand equivalent and silica sesquioxide ratio, in addition to a Methylene Blue spot test, linear shrinkage, MCT classification and X-ray diffraction. The results show that the sand equivalent alone is not able to evaluate the content of impurities of the clay fraction; it needs to be performed along with the Methylene Blue spot test. Linear shrinkage proved to be an important indicator of plasticity, capable of measuring small values of plasticity. Finally, the MCT classification precisely indicated the lateritic behavior of the samples. stable standards region base limit ratio test Xray X ray diffraction Finally samples

A direct-doping method was tested to design new composite-glasses by incorporating lanthanum niobate nanocrystals (NC) in tellurite glasses. NC powder were grinding with glass powder before heating-quenching, with the main investigation approached of best parameters for NC suitable homogenization but limited dissolution. Thermal analysis signalizes that prior heat-treatment of NC promotes higher transparency and limits NC dissolution. These materials with visually detectable NC aggregates exhibited glass transition temperatures close to the starting glass. LaNbO4 phase was hardly detected by X-ray diffraction because of the low weight ratio and partial dissolution but the monoclinic polymorph could be identified for lower time. UV-visible-NIR transmission spectra also related progressive lower transparency with light scattering of NC aggregates. Photoluminescence suggest that lower times allowed to ensure the NC environment with lower crystallinity around Eu3+-ions in final composite-glass. These results pave the way for designing new materials containing NC not achievable by conventional nucleation-growth methods. directdoping direct doping compositeglasses composite glasses (NC heatingquenching, heatingquenching heating quenching, quenching heating-quenching heattreatment heat treatment LaNbO Xray X ray time UVvisibleNIR UV visible NIR Eu3+ions Eu3ions Euions Eu3+ ions Eu3 Eu compositeglass. compositeglass composite-glass nucleationgrowth nucleation growth methods

Abstract The present work describes the use of a simulation model based on asymptotic methods (ray tracing) on the propagation of ultra-wideband radio signals in a densely-arborized urban channel. The model was previously validated and adjusted using data obtained from measurement campaigns in the millimeter-wave band in locations different from the one to be analyzed here. The simulation uses deterministic methods to predict the received power, cross-polar discrimination, root mean square delay spread, and mean delay in a channel with a high density of scatterers (trees, buildings, and poles). Simulated signals were transmitted in the vertical and horizontal polarizations, considering non-specular reflections caused by rough surfaces and the effect of the transmitter’s height variation in outdoor channels.

RESUMO Objetivos: comparar os parâmetros do ciclo de atividade/descanso de puérperas lactantes no início do pós-parto sob regime de iluminação com raios de comprimento de onda longo controlado e descontrolado. Métodos: estudo quase-experimental com lactantes e seus bebês em alojamento conjunto, São Paulo, Brasil. Os participantes foram alocados para grupos experimental (intervenção) ou de comparação. A intervenção consistia na exposição em uma sala controlada com iluminação artificial de raios de comprimento de onda longo à noite. Foram analisados os horários de atividade/repouso (horas) e nível de 6-sulfatoximelatonina em 24 horas. Resultados: a atividade média e os tempos de repouso das mulheres nos grupos experimental e comparação foram semelhantes. Os percentuais médios de volume total de 6-sulfatoximelatonina durante o dia e a noite foram semelhantes (p=0,09). Em 24 horas, o grupo experimental apresentou percentual médio significantemente menor de volume total em relação ao grupo comparação (p=0,04). Conclusões: as mulheres que permaneceram no quarto com luz artificial de comprimento de onda longa não apresentaram diferenças nos níveis de atividade/repouso e 6-sulfatoximelatonina no início do período pós-parto.

ABSTRACT Objectives: to compare the parameters of the activity/rest cycle of early postpartum breastfeeding women under a controlled and uncontrolled long wavelength ray light regimen. Methods: quasi-experimental study with breastfeeding women and their babies during postnatal rooming-in, São Paulo, Brazil. Participants were allocated to either an experimental (intervention) or a comparison group. The intervention involved exposure of the woman in a controlled room with artificial long wavelength ray light at night. Each woman’s level of 6-sulfatoxymelatonin at 24 hours and activity/rest times was analyzed. Results: the mean activity/rest times of women in the experimental and comparison groups were similar. The mean percentages of total load of 6-sulfatoxymelatonin during the day and night were similar (p=0.09). At 24 hours, the experimental group presented a significantly lower mean percentage of total load compared to the comparison group (p=0.04). Conclusions: women who stayed in the room with long-wavelength artificial light showed no difference in activity/rest and 6-sulfatoxymelatonin levels in the early postpartum period.

RESUMEN Objetivos: comparar parámetros del ciclo actividad/descanso en madres lactantes en posparto temprano bajo régimen lumínico de rayos de longitud de onda larga controlado y no controlado. Métodos: estudio cuasiexperimental con madres lactantes y sus bebés, São Paulo, Brasil. Las participantes fueron asignadas a grupos experimental (intervención) y comparación, consistente en exposición en habitación controlada con luz artificial de rayos de longitud de onda larga durante la noche. Se analizaron tiempos de actividad/descanso (horas) y nivel de 6-sulfatoximelatonina a las 24 horas. Resultados: actividad media y tiempos de descanso fueron similares en grupos comparación e intervención. Porcentajes promedio de volumen total de 6-sulfatoximelatonina durante día y noche resultaron similares (p=0,09). A las 24 horas, el grupo intervención presentó porcentaje promedio de volumen total significantemente menor comparado con grupo comparación (p=0,04). Conclusiones: las mujeres expuestas a luz artificial de longitud de onda larga no mostraron diferencias en niveles actividad/descanso y 6-sulfatoximelatonina durante el posparto temprano.

Abstract The objective of this study was to analyse the initial medium-term growth of a P. reticulata settlement under different phosphorus doses. The experiment was carried out in an area of Atlantic Forest, Sooretama, Northern Espírito Santo State, Brazil. Five doses of P per each tree (0 g, 27 g, 47 g, 67 g and 87 g) were tested in a randomized block design with three replicates and 18 plants per plot. At 3 months, 9 months and 15 months, height and diameter were measured at the soil level. At 36 months height, diameter at breast height, survival, basal area, and nutritional evaluation of the trees were measured. A logistic model was also used to model the growth in height of individual trees and a logistic model considering fixed effects and mixed form (fixed and random effects), in order to verify if the inclusion of the random effect (tree) would result in gains in terms of accuracy in the estimation of the future height of P. reticulata trees. The species presents potential for use in reforestation programs under edaphoclimatic conditions tested and under similar conditions. The species was not very demanding in P, and the addition of this nutrient promotes negative effects on its growth in the short and medium term. Regarding the model of growth in height, the logistic model adjusted in the mixed form showed to be superior to the traditional adjustment.

Resumen El objetivo de este estudio fue analizar el crecimiento inicial a mediano plazo de un asentamiento de P. reticulata bajo diferentes dosis de fósforo. El experimento se llevó a cabo en un área del Bosque Atlántico, Sooretama, norte del estado de Espírito Santo, Brasil. Se probaron cinco dosis de P por árbol (0 g, 27 g, 47 g, 67 g y 87 g) en un diseño de bloques al azar con tres repeticiones y 18 plantas por parcela. A los 3 meses, 9 meses y 15 meses se midió la altura y el diámetro a nivel del suelo. A los 36 meses de la siembra, se midió el diámetro a la altura del pecho, la supervivencia y el área basal y se hizo una evaluación nutricional de los árboles. También se utilizó un modelo logístico para modelar el crecimiento en altura de árboles individuales y el modelo logístico considerando efectos fijos y forma mixta (efectos fijos y aleatorios) para verificar si la inclusión del efecto aleatorio (árbol) resultaría en ganancias en términos de precisión en la estimación de la altura futura de los árboles de P. reticulata. La especie presenta potencial para su uso en programas de reforestación en condiciones edafoclimáticas probadas y en condiciones similares. La especie no fue muy exigente en fósforo y la adición de este nutriente promovió efectos negativos en su crecimiento a corto y mediano plazo. Con respecto al modelo de crecimiento en altura, el modelo logístico ajustado en forma mixta mostró ser superior al ajuste tradicional.

Abstract In this paper, we present in details a method for determining the soil density of disturbed samples. The mass attenuation coefficient was also evaluated by using the relation between the number of photon counts and the path length (soil density \texttimes thickness). A typical student laboratory setup (PASCO) was utilized in the measurements. A gamma ray source of 137 Cs and soils with four different textural classes were employed. The experimental apparatus here proposed, that uses an educational gamma ray attenuation system, permitted measuring, with very good agreement with the traditional method, the density of soil samples. The experiment can be somehow extended by proposing the investigation of soil bulk variations due, for instance, to soil compaction, a subject of interest for engineering and environmental physics students.

Resumo Apresentamos, neste artigo, um estudo teórico sobre os limites físicos associados a uma partícula fundamental, o fóton, na escala de Planck. Além disso, calculamos a temperatura de um buraco negro com as dimensões de Planck. A partir da análise dimensional, verificamos cinco unidades da escala de Planck (massa, tempo, comprimento, energia e temperatura). Primeiramente, analisamos um fóton com dimensões do comprimento de Planck; em seguida, identificamos a energia deste fóton com o comprimento de onda da ordem do raio de Schwarzschild ( r s ). Por fim, calculamos a temperatura de um buraco negro com as dimensões de Planck (no caso, com seu raio de Schwarzschild igual ao comprimento de Planck). O “raio do fóton” aparece como um múltiplo do comprimento de Planck, demonstrando a inacessibilidade de escalas menores que a de Planck devido ao Princípio da Incerteza. Dentre os resultados obtidos, podemos destacar três caminhos possíveis para a escala de Planck, bem como a mensuração do menor fóton possível de acordo com as leis da Física, que se caracteriza por máxima frequência e energia.

Abstract In this paper we present a theoretical study of the physical limits associated with a fundamental particle, the photon, in the Planck scale. In addition, we calculated the temperature of a black hole with Planck dimensions. From the dimensional analysis, we verified five units of the Planck scale (mass, time, length, energy, and temperature). First, we analyze a photon with dimensions of Planck length; Then we identify the energy of this photon with the wavelength of the order of the Schwarzschild ray ( r s ). Finally, we calculate the temperature of a black hole with Planck's dimensions (in this case, with its Schwarzschild radius equal to the Planck's length). The “photon ray” appears as a multiple of Planck's length, demonstrating the inaccessibility of scales smaller than Planck's due to the Uncertainty Principle. Among the results obtained, we can highlight three possible paths to the Planck scale, as well as the smallest possible photon measurement according to the laws of physics, which is characterized by maximum frequency and energy.

Abstract Aluminum bronze alloy is applied in environments that require materials of high mechanical resistance and wear, such as marine, oil & gas and aerospace ones. This study analyzes the densification of composites based on aluminum bronze with additions of the vanadium (VC) and niobium (NbC) carbides, and the influence of these carbides in the milling efficiency and improvement of the diffusion process between particles to obtain better results for density and porosity. The composites were produced by powder metallurgy from aluminum bronze powders obtained from the mechanical milling process of discarded scraps. The efficiency of the sintering process depends on parameters, such as the time and temperature of sintering, together with the size of the particles obtained from the milling process. This study aimed to obtain and characterize the composites produced by the powder metallurgy route, with NbC and VC addition and to analyze physical properties, such as density and porosity. The powder morphologies, particle sizes and samples sintered were performed by scanning electron microscopy (SEM), X ray diffraction (XRD), laser diffraction analysis and optical microscopy (OM). The results indicate that addition of VC improves the milling efficiency, when compared to NbC addition, since it promotes a greater reduction of the particle size, directly favoring the sintering process. In this case, to achieve similar particle size, twice the milling time was required when NbC was used. The density values achieve ~ 73% of reference material for VC addition and ~ 68% for NbC and porosities varying between 27% and 38%.

Abstract We applied a method of Simultaneous Prestack Seismic Inversion (SPSI) in a hydrocarbon field located in the Campos Basin, Brazil. The goal was to study the application of this method to Albian carbonate rocks of the Quissamã Formation. Based on what is found in nearby fields, this Formation potentially contains hydrocarbon accumulations that can be revealed with the inverted models. P-wave velocity (Vp), S-wave velocity (Vs) and density (ρ) curves along seven wells were used as inputs to construct 3-D initial models of acoustic impedance (Zp), shear impedance (Zs) and ρ. Wells without Vs and ρ curves had those values calculated from well-established equations. Final 3-D models were calculated from deviations in linear relationships between the logarithms of Zs and Zp, as well as between ρ and Zp, which were merged with the initial models. Interpretations of the inversion results were conducted based on patterns found along well logs such as resistivity (ILD), gamma ray (GR), density (RHOB), neutron porosity (NPHI) and sonic (DT). These analyses provided criteria to select the best inverted models. These models show low impedance anomalies that are consistent with previous studies performed with the well logs. One well in particular was interpreted as having high potential to contain hydrocarbons. This well shows an impedance pattern that allowed us to highlight other areas with the same pattern throughout the entire seismic volume.

RESUMO Casearia sylvestris SW é uma espécie perene altamente adaptável que é encontrada em toda a América Latina e amplamente disseminada no Brasil. Este trabalho analisou as características ecológicas da anatomia da madeira de C. sylvestris ocorrendo em três tipos de ecossistemas: Cerrado, Floresta da Galeria (Norte de Minas Gerais) e Mata Atlântica (Sul de Minas Gerais). As características qualitativas foram semelhantes entre as plantas nos três ecossistemas, diferindo apenas na distribuição de máculas e tiloses próximas a máculas que eram mais frequentes no Cerrado e na Floresta da Galeria. Os resultados quantitativos mostraram diferenças significativas para vários parâmetros, bem como variação entre indivíduos dos tipos de vegetação do Norte e do Sul de Minas Gerais. A matriz de correlação entre as variáveis, características anatômicas quantitativas, características do solo, altura e diâmetro das plantas, mostrou que as plantas foram agrupadas por tipo de ecossistema. Casearia sylvestris pode adotar diferentes estratégias de sobrevivência em relação à segurança e eficiência do transporte de água pela adaptação ecológica da anatomia da madeira. As características anatômicas adaptativas à seca foram principalmente uma diminuição da frequência do vaso e um aumento da largura e frequência dos raios.

ABSTRACT Casearia sylvestris SW (Salicaceae) is a highly adaptive perennial species that is found throughout Latin America and widely spread in Brazil. This work analyzed the ecological features of wood anatomy of C. sylvestris occurring in three ecosystem types: Cerrado, Gallery Forest (Northern of Minas Gerais) and Mata Atlântica (Southern of Minas Gerais). Qualitative features were similar among plants in the three ecosystems, differing only in the distribution of pith flecks and neighboring tyloses that were more frequent in Cerrado and Gallery Forest. The quantitative results showed significant differences for several parameters, as well as variation between individuals of vegetation types of Northern and Southern of Minas Gerais. The correlation matrix of variables including quantitative anatomical characteristics, soil characteristics, height and diameter of the plants showed that plants were grouped by ecosystem type. Casearia sylvestris might adopt different survival strategies regarding safety and efficiency of water transport by wood anatomy ecological adaptation. The adaptive anatomical features to drought were mostly an decrease of vessel frequency and an increase of ray width and frequency.

ABSTRACT The application of quantitative methods to digital soil and geomorphological mapping is becoming an increasing trend. One of these methods, Geomorphons, was developed to identify the ten most common landforms based on digital elevation models. This study aimed to make a quantitative assessment of the relationships between Geomorphons units, determined at three spatial resolutions and nine radii, and soil types and properties of two watersheds with different soil-landscape relationships in Brazil to help soil surveying and mapping under tropical conditions. The study was conducted at Lavrinha Creek (LCW) and Marcela Creek (MCW) watersheds, located in the state of Minas Gerais, Brazil. Spatial resolutions of 10, 20 and 30 m were the basis for generating Geomorphons at 9 radii of calculation for the watersheds. They were overlapped to detailed soil maps of the watersheds and a chi-square test was carried out to assess their relationship with soil types. Observation points were compared with the most highly correlated Geomorphons to also assess relationships with soil properties. Geomorphons with resolution of 30-m and radii of 20 and 50 cells, respectively for LCW and MCW, were more highly correlated with the variability of soil types, in accordance with the terrain features of these watersheds. The majority of observation points for each soil type was located in the same Geomorphon unit that was dominant when analyzing soil maps. There was less variability in soil properties between Geomorphon units, which was probably due to the highly weathered-leached stage of soils. Geomorphons can help to improve soil maps in tropical conditions when assessing soil variability due to its high correlation with tropical soil types variability.

Resumo O cultivo de bivalves é de grande interesse econômico e social no Nordeste (NE) do Brasil. O policultivo é uma alternativa ao monocultivo tradicional de camarões para reduzir o impacto ambiental e melhorar a produção de ostras.Perkinsus marinus e Perkinsus olseni foram identificados infectando ostras no Nordeste do Brasil e representam uma ameaça a produção de ostras. Este estudo avaliou a ocorrência dePerkinsus spp. em Crassostrea gasardurante todas as fases de produção. Sementes de ostras foram produzidas em laboratório e cultivadas em viveiros de camarão no Rio Grande do Norte.Perkinsus spp. foram diagnosticados com o uso do meio de tioglicolato fluido de Ray e confirmado por reação em cadeia da polimerase. A prevalência e intensidade de infecção foram determinadas em ostras até atingirem 7 cm. Os resultados mostraram que os reprodutores encontravam-se infectados porPerkinsus (60%), mas as sementes produzidas estavam livres de Perkinsus. As sementes adquiriram a infecção porPerkinsus quando transferidas para os viveiros. A prevalência aumentou gradualmente nos sete meses após a colocação nos viveiros (73%) e, em seguida, diminuiu para 17% até o décimo mês. As infecções foram inicialmente leves, mas aumentaram até a fase final do crescimento. Em conclusão, é possível produzir sementes de ostras C. gasarlivres de Perkinsus a partir de reprodutores infectados e seu cultivo em viveiros de camarão é viável.

Abstract Bivalve culture is of considerable economic and social interest in northeastern (NE) Brazil. The polyculture is an alternative approach to traditional monoculture for reducing the environmental impact of shrimp farming and improving oyster culture. Perkinsus marinus andPerkinsus olseni were found infecting oysters in NE Brazil and can threaten oyster production. This study evaluatedPerkinsus spp. occurrence in Crassostrea gasar during all production stages. Oyster spats were produced in a hatchery and grown in shrimp ponds in Rio Grande do Norte state.Perkinsus spp. were surveyed by Ray’s fluid thioglycollate medium and confirmed by polymerase chain reaction. Prevalence and intensity of infection were determined in oysters until they reached 7 cm. Results showed that the broodstock was already infected by Perkinsus (60%), but the derived spats were Perkinsus-free. Oyster spats acquired Perkinsus infection when transferred to ponds. The prevalence gradually increased in the seven months following placement in ponds (73%), and then decreased to 17% by the tenth month. The infections were initially mild, but intensity increased at the final growth stage. In conclusion, it is possible to produce Perkinsus-free C. gasar oyster spats from infected broodstock, and their culture in shrimp ponds is feasible.

OBJETIVO: verificar os efeitos de diferentes métodos de esterilização/desinfecção nas propriedades mecânicas de elásticos ortodônticos em cadeia. MÉTODOS: segmentos de elástico em cadeia com 5 elos cada foram enviados para esterilização em radiação gama com cobalto 60 (20 KGy). Após esterilização, esses foram contaminados com amostras clínicas de Streptococcus mutans. Passado esse período, foram submetidos aos testes de esterilização/desinfecção por diferentes métodos, formando seis grupos de estudo, assim denominados: Grupo 1 (controle - sem ter sido contaminado), Grupo 2 (álcool 70°GL), Grupo 3 (autoclave), Grupo 4 (ultravioleta), Grupo 5 (ácido peracético) e Grupo 6 (glutaraldeído). Após esterilização/desinfecção, avaliou-se a efetividade desses métodos, por meio de contagem de unidades formadoras de colônias por mL (UFC/mL), e as propriedades mecânicas desses materiais. Utilizou-se o teste t de Student para avaliar o número de UFC, além do ANOVA e, posteriormente, do teste de Tukey para avaliação da força. RESULTADOS: verificou-se que o ultravioleta não obteve eficácia total quanto à esterilização. E não ocorreu perda das propriedades mecânicas dos elásticos, com os diferentes métodos de esterilização utilizados (p > 0,05). CONCLUSÃO: o controle biológico de elásticos em cadeia não interfere nas suas propriedades mecânicas.

OBJECTIVE: To investigate the effects of different sterilization/disinfection methods on the mechanical properties of orthodontic elastomeric chains. METHODS: Segments of elastomeric chains with 5 links each were sent for sterilization by cobalt 60 (Co60) (20 KGy) gamma ray technology. After the procedure, the elastomeric chains were contaminated with clinical samples of Streptococcus mutans. Subsequently, the elastomeric chains were submitted to sterilization/disinfection tests carried out by means of different methods, forming six study groups, as follows: Group 1 (control - without contamination), Group 2 (70°GL alcohol), Group 3 (autoclave), Group 4 (ultraviolet), Group 5 (peracetic acid) and Group 6 (glutaraldehyde). After sterilization/disinfection, the effectiveness of these methods, by Colony forming units per mL (CFU/mL), and the mechanical properties of the material were assessed. Student's t-test was used to assess the number of CFUs while ANOVA and Tukey's test were used to assess elastic strength. RESULTS: Ultraviolet treatment was not completely effective for sterilization. No loss of mechanical properties occurred with the use of the different sterilization methods (p > 0.05). CONCLUSION: Biological control of elastomeric chains does not affect their mechanical properties.

This work aims to analyze chemically the surface of pure titanium commercial implants, currently used in dentistry. Eight implants were selected from the following manufacturers: Conexão sistema de prótesis; Lifecore - Biomedical; as technology and s Serson International. The samples showed surface treatment through acid attack techniques (conexão) and titanium plasma spray (Lifecore - Biomedical; technology as and s-Serson International), being divided into four groups containing two implants of the same batch of each manufacturer. Analyses were performed by x- ray excited (XPS) photoelectron spectroscopy. The results of chemical analysis showed the elements Titanium (Ti), Oxygen (O), Silicon (Si), Zinc (Zn), Aluminum (Al) and Carbon (C). It can be concluded that there are impurities in the implant surface, although further studies are needed that associate the presence of these compounds and their interference in osseointegration.

Este trabajo tiene como objetivo analizar, químicamente la superficie de implantes de titanio comercialmente puro, utilizados actualmente en la odontología. Fueron seleccionados ocho implantes de las siguientes marcas: Conexão Sistema de Prótesis; Lifecore - Biomedical; AS Technology y S Serson Internacional. Las muestras presentaron tratamiento de superficie a través de las técnicas de ataque ácido (Conexão) y plasma spray de titanio (Lifecore - Biomedical; AS Technology y S Serson International). Fueron divididas en cuatro grupos, conteniendo dos implantes del mismo lote de cada fabricante. Los análisis fueron realizados a través de espectroscopía de fotoelectrones excitada por rayos-X (XPS). Los resultados de los análisis químicos mostraron los elementos de titanio (Ti), oxígeno (O), silicio (Si), zinc (Zn), aluminio (Al) y carbono (C). Se puede concluir que hay impurezas en las superficies de los implantes, aunque se necesitan más trabajos que relacionen la presencia de estos compuestos y su interferencia en la oseointegración.

Trichomycterus dali, espécie nova, é descrita de cavernas calcárias alagadas na área cárstica da Serra da Bodoquena, estado do Mato Grosso do Sul, Brasil central. A nova espécie é diagnosticada por um caráter único no gênero, a presença de dobras adiposas conspícuas, em forma de crista, passando por toda a região dorsal do corpo. Trichomycterus dali pode ser ainda diferenciada facilmente de suas congêneres epígeas pela redução dos olhos e da pigmentação cutânea (exceto para T. gorgona), e das congêneres restantes (isto é, todas as hipógeas mais T. gorgona) pela perda total dos olhos, não visíveis externamente (exceto para T. sandovali e T. spelaeus). Outras características diagnósticas incluem barbilhões muito longos, especialmente o nasal (99,3-143,5% do comprimento da cabeça) e o maxilar (97,0-131,3% do comprimento da cabeça), contagem de raios da nadadeira peitoral atingindo I,9 e uma fontanela cranial única com uma constrição conspícua no ponto de encontro do supraoccipital e dos dois ossos frontais. O status troglóbio da espécie é sugerido pela presença de troglomorfismos em avançado grau, especialmente a redução da pigmentação cutânea, a perda total dos olhos e os barbilhões alongados. Além disso, a presença de uma dobra adiposa bem desenvolvida nos adultos pode indicar uma adaptação distintiva, adquirida por neotenia, para enfrentar as condições alimentares escassas do seu habitat hipógeo.

Trichomycterus dali, new species, is described from flooded limestone caves in Serra da Bodoquena karst area, State of Mato Grosso do Sul, Central Brazil. The new species is diagnosed by a unique character in the genus, the presence of conspicuous, ridge-like adipose folds lining dorsally throughout the body. Trichomycterus dali can be further distinguished readily from epigean congeners by the reduction of eyes and skin pigmentation (except for T. gorgona), and from remaining congeners (i.e., all hypogean plus T. gorgona) by the total loss of eyes, not visible externally (except for T. sandovali and T. spelaeus). Other diagnostic features includes very long barbels, especially the nasal (99.3-143.5% HL) and the maxillary (97.0-131.3% HL), pectoral-fin ray count reaching I,9 and a unique cranial fontanel with a conspicuous constriction on the meeting point of supraoccipital and the two frontal bones. The troglobitic status of the species is suggested by the presence of troglomorphisms on an advanced degree, especially the reduction of skin pigmentation, the total loss of eyes and the enlarged barbels. In addition, the presence of a well developed adipose fold in adults may indicate a distinctive adaptation acquired by neoteny to withstand the food scarce conditions of its hypogean habitat.