B chromosomes in species of the genus Prochilodus (Characiformes, Prochilodontidae): morphological identity and dispersion

Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP)

Genetic isolation and morphological divergence of Black Sea bottlenose dolphins

The Black Sea is a semi-enclosed body of water that differs from the adjacent Mediterranean Sea in terms of its biodiversity, oceanographical and ecological characteristics. There is growing international concern about pollution in the Black Sea and other anthropogenic threats to its fauna. The bottlenose dolphin (Tursiops truncatus) is one of three species of cetaceans living in the Azov-Black Sea basin. Despite considerable research on bottlenose dolphins elsewhere, the extent of human impacts on the Black Sea populations is unknown. Previous attempts to award special conservation status to Black Sea cetaceans have failed specifically because policy makers have viewed their ecological and evolutionary uniqueness as equivocal. This study assessed divergence between Black Sea, Mediterranean Sea and Atlantic Ocean bottlenose dolphins for 26 cranial measurements (n = 75 adult bottlenose dolphin skulls) and mitochondrial DNA (n = 99 individuals). Black Sea bottlenose dolphins are smaller than those in the Mediterranean, and possess a uniquely shaped skull. As in a previous study, we found the Black Sea population to be genetically distinct, with relatively low levels of mtDNA diversity. Population genetic models suggest that Black Sea bottlenose dolphins have so little gene flow with the Mediterranean due to historical isolation that they should be managed separately.

The Phylogenetic Relationships and Biogeography of True Porpoises (Mammalia: Phocoenidae) Based On Morphological Data

Prior studies of phylogenetic relationships among phocoenids based on morphology and molecular sequence data conflict and yield unresolved relationships among species. This study evaluates a comprehensive set of cranial, postcranial, and soft anatomical characters to infer interrelationships among extant species and several well-known fossil phocoenids, using two different methods to analyze polymorphic data: polymorphic coding and frequency step matrix. Our phylogenetic results confirmed phocoenid monophyly. The division of Phocoenidae into two subfamilies previously proposed was rejected, as well as the alliance of the two extinct genera Salumiphocaena and Piscolithax with Phocoena dioptrica and Phocoenoides dalli. Extinct phocoenids are basal to all extant species. We also examined the origin and distribution of porpoises within the context of this phylogenetic framework. Phocoenid phylogeny together with available geologic evidence suggests that the early history of phocoenids was centered in the North Pacific during the middle Miocene, with subsequent dispersal into the southern hemisphere in the middle Pliocene. A cooling period in the Pleistocene allowed dispersal of the southern ancestor of Phocoena sinusinto the North Pacific (Gulf of California).

Application of Mossbauer spectroscopy to the study of corrosion resistance in NaCl solution of plasma nitrided AISI 316L stainless steel

Corrosion research in steels is one of the areas in which Mossbauer spectroscopy has become a required analytical technique, since it is a powerful tool for both identifying and quantifying distinctive phases (which contain Fe) with accuracy. In this manuscript, this technique was used to the study of corrosion resistance of plasma nitrided AISI 316L samples in the presence of chloride anions. Plasma nitriding has been carried out using dc glow-discharge, nitriding treatments, in medium of 80 vol.% H-2 and 20 vol.% N-2, at 673 K, and at different time intervals: 2, 4, and 7 h. Treated samples were characterized by means of phase composition and morphological analysis, and electrochemical tests in NaCl aerated solution in order to investigate the influence of treatment time on the microstructure and the corrosion resistance, proved by conversion electron Mossbauer spectroscopy (CEMS), glancing angle X-ray diffraction (GAXRD), scanning electron microscopy (SEM) and potentiodynamic polarization. A modified layer of about 8 gin was observed for all the nitrided samples, independently of the nitriding time. A metastable phase, S phase or gamma(N), was produced. It seems to be correlated with gamma`-Fe-4 N phase. If the gamma(N) fraction decreases, the gamma` fraction increases. The gamma(N) magnetic nature was analyzed. When the nitriding time increases, the results indicate that there is a significant reduction in the relative fraction of the magnetic gamma(N) (in) phase. In contrast, the paramagnetic gamma(N) (p) phase increases. The GAXRD analysis confirms the Mossbauer results, and it also indicates CrN traces for the sample nitrided for 7 h. Corrosion results demonstrate that time in the plasma nitriding treatment plays an important role for the corrosion resistance. The sample treated for 4 h showed the best result of corrosion resistance. It seems that the epsilon/gamma` fraction ratio plays an important role in thin corrosion resistance since this sample shows the maximum value for this ratio. (c) 2008 Published by Elsevier B.V.

Chemical and morphological features of nanofilled composite resin: Influence of finishing and polishing procedures and fluoride solutions

This study evaluated the influence of finishing and polishing procedures and different fluoride solutions on superficial morphology and chemistry of the nanofilled composite resin Supreme XT (3M) through the EDX analysis and SEM evaluation. Circular specimens (n = 30) of 10 mm diameter and 2 mm thickness were prepared, with half of the sample assays finished and polished with Super-Snap (R) sandpaper. The experimental groups were divided according to the presence or absence of finishing and polishing and solutions (artificial saliva, 0.05% of manipulated sodium fluoride solution, Fluordent Reach, Oral B, Fluorgard). Specimens were immersed in each respective solution for 1 min per day, during 60 days and stored in artificial saliva at 37 +/- 1 degrees C between immersion periods. Topography and chemical analysis was qualitative. It was observed that specimens submitted to finishing and polishing procedures had lower superficial degradation. Fluoride solutions promoted superficial alterations on specimens, being the highest degradation obtained with Fluordent Reach. It can be concluded that finishing and polishing procedures and the immersion media influence the superficial morphology of composite resin tested; the Fluordent Reach was the fluoride solution that most affected the material's surface. Microsc. Res. Tech. 2011., (c) 2011 Wiley Periodicals, Inc.

Influence of effective number of pulses on the morphological structure of teeth and bovine femur after femtosecond laser ablation

Femtosecond lasers have been widely used in laser surgery as an instrument for contact-free tissue removal of hard dental, restorative materials, and osseous tissues, complementing conventional drilling or cutting tools. In order to obtain a laser system that provides an ablation efficiency comparable to mechanical instruments, the laser pulse rate must be maximal without causing thermal damage. The aim of this study was to compare the different morphological characteristics of the hard tissue after exposure to lasers operating in the femtosecond pulse regime. Two different kinds of samples were irradiated: dentin from human extracted teeth and bovine femur samples. Different procedures were applied, while paying special care to preserving the structures. The incubation factor S was calculated to be 0.788 +/- 0.004 for the bovine femur bone. These results indicate that the incubation effect is still substantial during the femtosecond laser ablation of hard tissues. The plasma-induced ablation has reduced side effects, i.e., we observe less thermal and mechanical damage when using a superficial femtosecond laser irradiation close to the threshold conditions. In the femtosecond regime, the morphology characteristics of the cavity were strongly influenced by the change of the effective number of pulses. (C) 2012 Society of Photo-Optical Instrumentation Engineers (SPIE). [DOI: 10.1117/1.JBO.17.4.048001]

Contextual Reading and Metalinguistic Processing in Brazilian Portuguese: A Longitudinal Study

Metalinguistic skill is the ability to reflect upon language as an object of thought. Amongst metalinguistic skills, two seem to be associated with reading and spelling: morphological awareness and phonological awareness. Phonological awareness is the ability of reflecting upon the phonemes that compose words, and morphological awareness is the ability of reflecting upon the morphemes that compose the words. The latter seems to be particularly important for reading comprehension and contextual reading, as beyond phonological information, syntactic and semantic information are required. This study is set to investigate - with a longitudinal design - the relation between those abilities and contextual reading measured by the Cloze test. The first part of the study explores the relationship between morphological awareness tasks and Cloze scores through simple correlations and, in the second part, the specificity of such relationship was inquired using multiple regressions. The results give some support to the hypothesis that morphological awareness offers an independent contribution regarding phonological awareness to contextual reading in Brazilian Portuguese.

A study of effectiveness of midazolam sedation for prevention of myocardial arrhythmias in endosseous implant placement

Purpose: The study aimed to assess electrocardiographic alterations during oral implant placement surgeries under local anesthesia (lidocaine chlorhydrate with epinephrine), using 15 mg of midazolam as an anxiolytic premedication. Material and methods: The study randomly selected 20 patients, aged 21-50 years old, requiring bilateral mandibular dental implants. Each patient was assessed using placebo on one side and midazolam on the contralateral side, with random, double-blinded distribution. The electrocardiogram recorded 12 static leads every 2 min, while D2 derivations were recorded continuously. Results: No statistically significant differences were observed between the placebo and midazolam when analyzing the morphological behavior of the electrocardiographic wave and the presence of arrhythmias during the experiment. However, under sedation, assessment of the behavior of electrocardiographic parameters during different stages of the procedure revealed statistically significant differences (P<0.05) for heart rate, P-wave amplitude and duration of the RR and QTc intervals. The arrhythmias detected were considered low risk for patients without systemic alterations and were observed in 53.3% of patients. The most frequently occurring alterations were tachycardia, bradycardia, supraventricular and ventricular extrasystoles and blocked atrial extrasystole, which were similar for both placebo and midazolam, with the greatest incidence during the initial, incision and bone drilling stages. Conclusion: The use of 15 mg of midazolam made no difference compared with the placebo. The use of 15 mg of midazolam did not show an advantage in the incidence of arrhythmias The anxiolytic premedication does not prevent myocardial arrhythmias in endosseous implant placement. The clinical significance of the arrhythmias may not represent serious risks.

Morphological description of the mouthparts of the Asian citrus psyllid, Diaphorina citri Kuwayama (Hemiptera: Psyllidae)

Scanning (SEM) and transmission (TEM) electron microscopy were used to elucidate the morphology of the rostrum, as well as the mandibular and maxillary stylets of the psyllid Diaphorina cirri, vector of phloem-inhabiting bacteria associated with citrus huanglongbing (HLB) disease. D. cirri has a cone-shaped rostrum that extends behind the pair of prothoracic coxae. The stylet bundle comprises a pair of mandibular (Md) and maxillary (Mx) stylets with a mean length of 513.3 mu m; when retracted, their proximal portions form a loop and are stored in the crumena (Cr). Serial cross-sections of the rostrum revealed that the mandibles are always projected in front of the maxillary stylets. The two maxillary stylets form the food and salivary canals, with diameters of 0.9 mu m and 0.4 mu m respectively. These two canals merge at the end of the stylets forming a common duct with a length of 4.3 mu m and a mean diameter of 0.9 mu m. The acrostyle, a distinct anatomical structure present in the common duct of aphid maxillary stylets, was not observed by TEM in the ultrathin cross-sections of the common duct (CD) of D. citri. This study provides new information on D. citri mouthparts that may help to understand the behaviour of this important vector of HLB-associated bacteria. (C) 2011 Elsevier Ltd. All rights reserved.

Three in one: fixing marine nematodes for ecological, molecular, and morphological studies

Multidisciplinary benthic studies are still hindered by the lack of a unique fixative that satisfactorily preserves morphology and DNA, and that is simultaneously adequate for ecological surveys. The objective of this study is to test the performance of five fixatives: formalin, ethanol, dimethylsulfoxide with EDTA and NaCl salts (DESS), methanol with acetic acid (METHAC), and ethanol with acetic acid (ETHAC), for the preservation of estuarine and exclusively marine nematode assemblages for morphological, molecular, and ecological studies. The presence of the stain rose bengal in each fixative was also evaluated in the yield of PCR reactions. For molecular analyses, one species of each habitat was considered. Results revealed that fixative performance for morphological studies is habitat-and species-dependent. For studies of estuarine sediment nematodes, we recommend the use of pure ethanol, because it caused little morphological distortion (<10% of the assemblage), preserved all the species for ecological studies, and yielded high quality DNA sequences. For studies of exclusively marine environments, METHAC or DESS are the most adequate. The first performed better for morphological and ecological surveys, whereas the second was more appropriate for molecular research. For ecological studies, DESS should be used in comparison with formalin, in order to cross check the results. Finally, staining of samples with rose bengal is not recommended, because it hindered DNA amplification regardless of the fixative used.

Transforming growth factor alpha immunoreactivity. A study in hepatocellular carcinoma and in non-neoplastic liver tissue

Background. Transforming growth factor alpha (TGF alpha) is an important mitogen that binds to epidermal growth factor receptor and is associated with the development of several tumors. Aims. Assessment of the immunoexpression of TGF alpha in hepatocellular carcinoma (HCC) and in non-neoplastic liver tissue and its relationship to morphological patterns of HCC. Material and methods. The immunohistochemical expression of TGF alpha was studied in 47 cases of HCC (27 multinodular, 20 nodular lesions). Five lesions measured up to 5 cm and 15 lesions above 5 cm. Thirty-two cases were graded as I or II and 15 as III or IV. The non-neoplastic tissue was examined in 40 cases, of which 22 had cirrhosis. HBsAg and anti-HCV were positive in 5/38 and 15/37 patients, respectively. The statistical analysis for possible association of immunostaining of TGF alpha and pathological features was performed through chi-square test. Results. TGF alpha was detected in 31.9% of the HCC and in 42.5% of the non-neoplastic. There was a statistically significant association between the expression of TGF alpha and cirrhosis (OR = 8.75, 95% CI = [1.93, 39.75]). The TGF alpha was detected more frequently in patients anti-HCV(+) than in those HBsAg(+). The immunoexpression of TGF alpha was not found related to tumor size or differentiation. In conclusion the TGF alpha is present in hepatocarcinogenesis in HBV negative patients. Further analysis is needed to examine the involvement of TGF alpha in the carcinogenesis associated with HCV and other possible agents. In addition, TGF alpha has an higher expression in hepatocyte regeneration and proliferation in cirrhotic livers than in HCC.

Morphological characterization of the progenitor blood cells in canine and feline umbilical cord

The umbilical cord blood (UCB) is an important source of hematopoietic stem cells with great deal of interest in regenerative medicine. The UCB cells have been extensively studied as an alternative to the bone marrow transplants. The challenge is to define specific methods to purify and characterize these cells in different animal species. This study is aimed at morphological characterization of progenitor cells derived from UCB highlighting relevant differences with peripheral blood of adult in dog and cats. Therefore, blood was collected from 18 dogs and 5 cats' umbilical cords from fetus in various developmental stages. The mononuclear cells were separated using the gradient of density Histopaque-1077. Characterization of CD34+ cells was performed by flow cytometric analysis and transmission electron microscopy. Granulocytes (ancestry of the basophiles, eosinophiles, and neutrophiles) and agranulocytes (represented by immature lymphocytes) were identified. We showed for the first time the ultrastructural features of cat UCB cells. Microsc. Res. Tech. 75:766770, 2012. (C) 2011 Wiley Periodicals, Inc.

Morphological profile of Brazilian jiu-jitsu elite athletes

Athletes from many sports that are categorized by body mass tend to reduce it to fit in lower categories. Such reduction can compromise the athlete's performance and health. In order to determine the most appropriate category, the body composition is highly relevant, especially to avoid excessive reduction. Thus, this study analyzed the morphological profile of Brazilian Jiu-Jitsu elite athletes. The sample was composed of 11 athletes, aged 25.8 +/- 3.3 years, medalists in national and/or international competitions. The analysis was performed to determine the anthropometric body composition and somatotype. Body fat percentage from this population was 10.3 +/- 2.6 % fat, a high percentage of muscle mass (61.3 +/- 1.5 %), and predominant mesomorphic component (5.5 +/- 1.0) was observed. The points of highest and lowest fat accumulation were respectively abdominal (15.7 +/- 6.3 mm) and chest (6.8 +/- 1.5 mm) regions. It can be concluded that athletes from this sport showed higher body mass during the preparatory period than in competitive conditions (4.4 +/- 2.4 %); however, they showed low body fat, high muscle mass percentage and predominant mesomorphic component.

Morphological structure of the liver in tambaqui, Colossoma macropomum (Cuvier, 1818)

This research aimed to describe the macroscopic and microscopic liver of tambaqui, Colossoma macropomum, Teleost freshwater Family Characidae, of great economic interest for the Amazon basin. We used six juveniles aged between six month and one year, from the small holding Esteio, Alta Floresta/MT, that develops mainly fish farming. The body was photographed in situ, described macroscopically, and fragments were removed and processed by routine histological techniques through paraffin embedding and HE staining. The liver, located ventrally to the swim bladder and craniodorsally to the stomach, is brownish red and consisted of three lobes, the right lateral, the left lateral and the ventral lobe. Microscopically, the parenchyma consists of hepatocytes varying from irregular rounded hexagonal to round forms with a large and central nucleus, and arranged in linear strings limited by sinusoids and radiating to central veins, but with absence of liver lobules. The central veins are distributed throughout the parenchyma, while the portal space consists in most cases only of a hepatic vein and bile duct; elsewhere exist artery and duct. Formation of portal triads was not founde. Melano macrophages were frequently seen dispersed throughout the central parenchyma. The morphofunctional study of the digestive system of fishes of the Amazon basin is important to obtain knowledge about their weight gain, large scale production for human consumption and preservation of the species, and has also its importance for being used as bioindicators today.

Evolutionary Insights from Bat Trypanosomes: Morphological, Developmental and Phylogenetic Evidence of a New Species, Trypanosoma (Schizotrypanum) erneyi sp nov., in African Bats Closely Related to Trypanosoma (Schizotrypanum) cruzi and Allied Species

Parasites of the genus Trypanosoma are common in bats and those of the subgenus Schizotrypanum are restricted to bats throughout the world, with the exception of Trypanosoma (Schizotrypanum) cruzi that also infects other mammals and is restricted to the American Continent. We have characterized trypanosome isolates from Molossidae bats captured in Mozambique, Africa. Morphology and behaviour in culture, supported by phylogenetic inferences using SSU (small subunit) rRNA, gGAPDH (glycosomal glyceraldehyde 3-phosphate dehydrogenase) and Cyt b (cytochrome b) genes, allowed to classify the isolates as a new Schizotrypanum species named Trypanosoma (Schizotrypanum) erneyi sp. nov. This is the first report of a Schizotrypanum species from African bats cultured, characterized morphologically and biologically, and positioned in phylogenetic trees. The unprecedented finding of a new species of the subgenus Schizotrypanum from Africa that is closest related to the America-restricted Trypanosoma (Schizotrypanum) cruzi marinkellei and T. cruzi provides new insights into the origin and evolutionary history of T. cruzi and closely related bat trypanosomes. Altogether, data from our study support the hypothesis of an ancestor trypanosome parasite of bats evolving to infect other mammals, even humans, and adapted to transmission by triatomine bugs in the evolutionary history of T. cruzi in the New World. (c) 2012 Elsevier GmbH. All rights reserved.