2,265 research outputs found

    Semen Cryopreservation in Brazilian Freshwater Fish: Advances and Main Challenges

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    Studies on semen cryopreservation in Brazilian freshwater fish have been growing in number of publications and investigated species. Despite this apparent increase in research, standardization of cryoprotocols is still missing, making it clear that the grounds on the quality of cryopreserved semen has not yet reached a level that guarantee satisfactory results for its replication. This chapter aims to make a critical and reflective analysis on the ways cryopreservation of freshwater fish semen has been conducted in Brazil. The difficulties in standardizing protocols, broodstock, and selection of genetically superior animals; the barriers in transferring technology from laboratory benches to the field and make feasible the use of cryopreserved semen on a commercial scale; the formation of germplasm banks and the responsible use of cryopreserved material are also discussed. We have no intention to point out the successes and mistakes that may have been committed in pursuing development of cryopreservation protocols, but a reflection on the future directions considering what should be pondered on this subject with objectivity and scientific consolidation

    Loading stress distribution in posterior teeth restored by different core materials under fixed zirconia partial denture: A 3d-fea study

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    Purpose: To evaluate the effect of different substrate stiffness [sound dentin (SD), resin composite core (RC) or metal core (MC)] on the stress distribution of a zirconia posterior three-unit fixed partial denture (FPD). Methods: The abutment teeth (first molar and first premolar) were modeled, containing 1.5 mm of axial reduction, and converging axial walls. A static structural analysis was performed using a finite element method and the maximum principal stress criterion to analyze the fixed partial denture (FPD) and the cement layers of both abutment teeth. The materials were considered isotropic, linear, elastic, homogeneous and with bonded contacts. An axial load (300 N) was applied to the occlusal surface of the second premolar. Results: The region of the prosthetic connectors showed the highest tensile stress magnitude in the FPD structure depending on the substrate stiffness with different core materials. The highest stress peak was observed with the use of MC (116.4 MPa) compared to RC and SD. For the cement layer, RC showed the highest values in the molar abutment (14.7 MPa) and the highest values for the premolar abutment (14.4 MPa) compared to SD (14.1 and 13.4 MPa) and MC (13.8 and 13.3 MPa). Both metal core and resin composite core produced adequate stress concentration in the zirconia fixed partial denture during the load incidence. However, more flexible substrates, such as composite cores, can increase the tensile stress magnitude on the cement

    Trace elements and isotopes analyses on historical samples of white sharks from the Mediterranean Sea

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    The white shark Carcharodon carcharias has been present in the Mediterranean Sea since 3.2 million years ago. Nevertheless, the current population shows a low genetic variability suggesting an endangered small population, on which there is scarce information regarding ecotoxicology or trophic ecology. Given that white shark's sightings are rare in the Mediterranean and the possibility of obtaining samples is highly limited, the aim of this research was to provide general information regarding the concentration of trace elements and stable isotopes (delta N-15 and delta C-13). Laboratory analyses were performed on 18 and 12 subsamples from two different white sharks' vertebrae obtained from two adult specimens caught in 1987, in Favignana Island, Italy. Perforations were made along the vertebrae to describe both trace elements and stable isotopes at different life stages. A total of 38 trace elements were analysed, in which the highest concentrations were found in Fe, Sr, U, Pb, and Zn. The fluctuations of these elements during the ontogeny of both individuals could have been related to changes in diet and environment, although the specific origin remains unknown. Regarding stable isotopes, the vertebrae from the male showed an isotopic range from 9.6 parts per thousand to 10.8 parts per thousand (delta N-15) and from -16.5 parts per thousand to -13.0 parts per thousand (delta C-13) with a mean +/- SD value of 10.3 +/- 0.4 parts per thousand for delta N-15 and -14.6 +/- 1.3 parts per thousand for delta C-13; whereas the female vertebrae had an isotopic range from 9.8 parts per thousand to 11.1 parts per thousand (delta N-15) and from -16.9 parts per thousand to -15.0 parts per thousand (delta C-13), with a mean +/- SD value of 10.8 +/- 0.6 parts per thousand for delta N-15 and -15.8 +/- 0.8 parts per thousand for delta C-13. There were no significant delta N-15 differences (U = 6, p = 0.07346) between the two individuals. However, there were just significant differences in delta C-13 (t = -1.8, p = 0.049256), which could suggest sexual segregation in terms of habitat use and feeding habits

    Síndrome de Pendred causada por mutação em homozigoze no gene SLC26A4 em uma família brasileira consangüínea

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    ABSTRACTPendred Syndrome (PS) is an autossomal recessive disorder characterized by sensorineural deafness, goiter and iodide organification defect. The hearing loss is associated with inner ear abnormalities, ranging from an isolated enlarged vestibular aqueduct (EVA) to a typical coclear dysplasia. Mutations in the gene that encodes pendrin (SLC26A4), a chloride/iodide transporter, have been shown to be associated with PS. We describe the clinical and molecular characteristics of a large consanguineous family harboring a mutation in the SLC26A4 gene. The proband was a 26-year-old deaf Brazilian woman who presented a bulky multinodular goiter and hypothyroidism since puberty. Five other siblings were deaf: one brother had a similar phenotype, three siblings also had goiters but normal thyroid function tests, and one brother had only a subtle thyroid enlargement. Other 4 siblings had no thyroid or hearing disorder. Parents were first degree cousins and had normal hearing. The mother was healthy, except for subclinical hypothyroidism; the father was deceased. A perchlorate test in the proband showed a discharge of 21% of the incorporated iodide 2h after the administration of 1g of KClO4. Audiological examinations showed profound hearing loss in all deaf subjects; CT and MRI of the temporal bones showed EVA in all of them. Genomic DNA was isolated from whole blood, from the 6 affected and 4 unaffected siblings, the mother and control. The coding region of the PDS gene (exons 2-21), including exon/intron boundaries, were amplified by PCR and sequenced. A single base-pair (T) deletion at position 1197 of exon 10 was detected in homozygous state in the 6 deaf siblings. The mother and 2 unaffected siblings were heterozygous for this mutation, which has been described by Everett et al. The 1197delT mutation is predicted to result in a frameshift and a truncated protein. The existence of PS phenocopies and intrafamilial phenotypic variability are well documented. The definite diagnosis requires molecular analysis. Our study illustrates the value and challenges of mutational analysis in selected patients with PS. __________________________________________________________________________________ RESUMOA syndrome de Pendred (SP) é uma doença autossômica recessiva caracterizada por surdez neurossensorial, bócio e defeito de organificação do iodo. A perda auditiva está associada a anormalidades do ouvido interno, desde a dilatação isolada do aqueduto vestibular (DAV) até uma típica displasia coclear. Mutações no gene que codifica a pendrina (SLC26A4), um transportador de cloreto/iodeto, têm sido associadas à SP. Descrevemos as características clínicas e moleculares de uma grande família consangüínea portadora de uma mutação no gene SLC26A4. O caso-índice era uma paciente do sexo feminino, brasileira, 26 anos, portadora de surdez congênita, que apresentava um volumoso bócio multinodular e hipotireoidismo desde a puberdade. Outros cinco irmãos eram surdos: um irmão tinha fenotipo semelhante, três também tinham bócio, porém com função tiroideana normal e um irmão tinha apenas um discreto aumento da tiróide. Outros quatro irmãos não apresentavam alteração tiroideana ou auditiva. Os pais eram primos de primeiro grau e tinham audição normal. A mãe era saudável, exceto por hipotireoidismo subclínico; o pai era falecido. O teste do perclorato no caso-índice revelou a liberação de 21% do iodo incorporado duas horas após a administração de 1 g de KClO4. Os exames audiológicos mostraram perda auditiva profunda em todos os indivíduos afetados; TC e RMN dos ossos temporais mostraram DAV em todos eles. O DNA genômico foi isolado do sangue total dos seis irmãos afetados e dos quatro não-afetados, da mãe e do controle. A região codificante do gene PDS (éxons 2-21), incluindo as junções éxon/íntron, foram amplificadas por PCR e seqüenciadas. Foi detectada a deleção de uma base (T) na posição 1197 do éxon 10, em homozigoze, nos seis irmãos afetados. A mãe e dois irmãos não-afetados eram heterozigotos para a mutação, que foi descrita inicialmente por Everett e cols. A mutação 1197delT provavelmente resulta em um erro de fase de leitura (frameshift) e em uma proteína truncada. A existência de fenocópias da SP e a variabilidade fenotípica intrafamiliar são bem conhecidas. O diagnóstico definitivo requer análise molecular. O presente estudo ilustra o valor e os desafios da análise mutacional em pacientes selecionados com SP

    The Perceived Benefits of Height: Strength, Dominance, Social Concern, and Knowledge among Bolivian Native Amazonians

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    Research in industrial countries suggests that, with no other knowledge about a person, positive traits are attributed to taller people and correspondingly, that taller people have slightly better socioeconomic status (SES). However, research in some non-industrialized contexts has shown no correlation or even negative correlations between height and socioeconomic outcomes. It remains unclear whether positive traits remain attributed to taller people in such contexts. To address this question, here we report the results of a study in a foraging-farming society of native Amazonians in Bolivia (Tsimane’)–a group in which we have previously shown little association between height and socioeconomic outcomes. We showed 24 photographs of pairs of Tsimane’ women, men, boys, and girls to 40 women and 40 men >16 years of age. We presented four behavioral scenarios to each participant and asked them to point to the person in the photograph with greater strength, dominance, social concern, or knowledge. The pairs in the photographs were of the same sex and age, but one person was shorter. Tsimane’ women and men attributed greater strength, dominance, and knowledge to taller girls and boys, but they did not attribute most positive traits to taller adults, except for strength, and more social concern only when women assessed other women in the photographs. These results raise a puzzle: why would Tsimane’ attribute positive traits to tall children, but not tall adults? We propose three potential explanations: adults’ expectations about the more market integrated society in which their children will grow up, height as a signal of good child health, and children’s greater variation in the traits assessed corresponding to maturational stages

    Multifunctional Hybrid MoS2-PEGylated/Au Nanostructures with Potential Theranostic Applications in Biomedicine

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    In this work, flower-like molybdenum disulfide (MoS2) microspheres were produced with polyethylene glycol (PEG) to form MoS2-PEG. Likewise, gold nanoparticles (AuNPs) were added to form MoS2-PEG/Au to investigate its potential application as a theranostic nanomaterial. These nanomaterials were fully characterized by scanning electron microscopy (SEM), transmission electron microscopy (TEM), X-ray diffraction (XRD), photoelectron X-ray spectroscopy (XPS), Fourier-transformed infrared spectroscopy (FTIR), cyclic voltammetry and impedance spectroscopy. The produced hierarchical MoS2-PEG/Au microstructures showed an average diameter of 400 nm containing distributed gold nanoparticles, with great cellular viability on tumoral and non-tumoral cells. This aspect makes them with multifunctional characteristics with potential application for cancer diagnosis and therapy. Through the complete morphological and physicochemical characterization, it was possible to observe that both MoS2-PEG and MoS2-PEG/Au showed good chemical stability and demonstrated noninterference in the pattern of the cell nucleus, as well. Thus, our results suggest the possible application of these hybrid nanomaterials can be immensely explored for theranostic proposals in biomedicine

    Formación universitaria en torno a la accesibilidad web: algunas experiencias en la FaCENA-UNNE

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    El artículo expone síntesis de varias experiencias en torno a la formación de recursos humanos de grado y posgrado centralizada en un aspecto de la calidad del software como es la Accesibilidad Web. Este tema, de trascendencia internacional, se aborda por diversas organizaciones y legislaciones. Se considera relevante fomentar la especialización en temas de Accesibilidad Web desde la Universidad dada su responsabilidad social. Además, se aporta desde la Universidad con recursos humanos que cómo agentes de cambio e innovación en la Industria del Software mejoraran los servicios de acceso a la información. Los resultados presentados indican la importancia de continuar con estas acciones con la finalidad de concientizar en lo relevante de incorporar los estándares de la Accesibilidad Web en los productos software.Sociedad Argentina de Informática e Investigación Operativ

    Formación universitaria en torno a la accesibilidad web: algunas experiencias en la FaCENA-UNNE

    Get PDF
    El artículo expone síntesis de varias experiencias en torno a la formación de recursos humanos de grado y posgrado centralizada en un aspecto de la calidad del software como es la Accesibilidad Web. Este tema, de trascendencia internacional, se aborda por diversas organizaciones y legislaciones. Se considera relevante fomentar la especialización en temas de Accesibilidad Web desde la Universidad dada su responsabilidad social. Además, se aporta desde la Universidad con recursos humanos que cómo agentes de cambio e innovación en la Industria del Software mejoraran los servicios de acceso a la información. Los resultados presentados indican la importancia de continuar con estas acciones con la finalidad de concientizar en lo relevante de incorporar los estándares de la Accesibilidad Web en los productos software.Sociedad Argentina de Informática e Investigación Operativ

    Mutation in the FUS nuclear localisation signal domain causes neurodevelopmental and systemic metabolic alterations

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    Variants in the ubiquitously expressed DNA/RNA-binding protein FUS cause aggressive juvenile forms of amyotrophic lateral sclerosis (ALS). Most FUS mutation studies have focused on motor neuron degeneration; little is known about wider systemic or developmental effects. We studied pleiotropic phenotypes in a physiological knock-in mouse model carrying the pathogenic FUSDelta14 mutation in homozygosity. RNA sequencing of multiple organs aimed to identify pathways altered by the mutant protein in the systemic transcriptome, including metabolic tissues, given the link between ALS-frontotemporal dementia and altered metabolism. Few genes were commonly altered across all tissues, and most genes and pathways affected were generally tissue specific. Phenotypic assessment of mice revealed systemic metabolic alterations related to the pathway changes identified. Magnetic resonance imaging brain scans and histological characterisation revealed that homozygous FUSDelta14 brains were smaller than heterozygous and wild-type brains and displayed significant morphological alterations, including a thinner cortex, reduced neuronal number and increased gliosis, which correlated with early cognitive impairment and fatal seizures. These findings show that the disease aetiology of FUS variants can include both neurodevelopmental and systemic alterations
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