376 research outputs found

    Sound production in the Meagre, Argyrosomus regius (Asso, 1801): intraspecific variability associated with size, sex and context

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    Many fish taxa produce sound in voluntary and in disturbance contexts but information on the full acoustic repertoire is lacking for most species. Yet, this knowledge is critical to enable monitoring fish populations in nature through acoustic monitoring.Portuguese Foundation for Science and Technology: PTDC/BIA-BMA/30517/2017; SFRH/BD/115562/2016; UID/MAR/04292/2019; UID/BIA/00329/2019; PTDC/BIA-BMA/29662/2017.info:eu-repo/semantics/publishedVersio

    Dynamics of Snoring Sounds and Its Connection with Obstructive Sleep Apnea

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    Snoring is extremely common in the general population and when irregular may indicate the presence of obstructive sleep apnea. We analyze the overnight sequence of wave packets --- the snore sound --- recorded during full polysomnography in patients referred to the sleep laboratory due to suspected obstructive sleep apnea. We hypothesize that irregular snore, with duration in the range between 10 and 100 seconds, correlates with respiratory obstructive events. We find that the number of irregular snores --- easily accessible, and quantified by what we call the snore time interval index (STII) --- is in good agreement with the well-known apnea-hypopnea index, which expresses the severity of obstructive sleep apnea and is extracted only from polysomnography. In addition, the Hurst analysis of the snore sound itself, which calculates the fluctuations in the signal as a function of time interval, is used to build a classifier that is able to distinguish between patients with no or mild apnea and patients with moderate or severe apnea

    Involvement of the clock gene Rev-erb alpha in the regulation of glucagon secretion in pancreatic alpha-cells

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    Disruption of pancreatic clock genes impairs pancreatic beta-cell function, leading to the onset of diabetes. Despite the importance of pancreatic alpha-cells in the regulation of glucose homeostasis and in diabetes pathophysiology, nothing is known about the role of clock genes in these cells. Here, we identify the clock gene Rev-erb alpha as a new intracellular regulator of glucagon secretion. Rev-erb alpha down-regulation by siRNA (60-70% inhibition) in alphaTC1-9 cells inhibited low-glucose induced glucagon secretion (p<0.05) and led to a decrease in key genes of the exocytotic machinery. The Rev-erb alpha agonist GSK4112 increased glucagon secretion (1.6 fold) and intracellular calcium signals in alphaTC1-9 cells and mouse primary alpha-cells, whereas the Rev-erb alpha antagonist SR8278 produced the opposite effect. At 0.5 mM glucose, alphaTC1-9 cells exhibited intrinsic circadian Rev-erb alpha expression oscillations that were inhibited by 11 mM glucose. In mouse primary alpha-cells, glucose induced similar effects (p<0.001). High glucose inhibited key genes controlled by AMPK such as Nampt, Sirt1 and PGC-1 alpha in alphaTC1-9 cells (p<0.05). AMPK activation by metformin completely reversed the inhibitory effect of glucose on Nampt-Sirt1-PGC-1 alpha and Rev-erb alpha. Nampt inhibition decreased Sirt1, PGC-1 alpha and Rev-erb alpha mRNA expression (p<0.01) and glucagon release (p<0.05). These findings identify Rev-erb alpha as a new intracellular regulator of glucagon secretion via AMPK/Nampt/Sirt1 pathway

    Review of the family Rivulidae (Cyprinodontiformes, Aplocheiloidei) and a molecular and morphological phylogeny of the annual fish genus Austrolebias Costa 1998

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    The family Rivulidae is the fourth most diverse clade of Neotropical fishes. Together with some genera of the related African family Nothobranchiidae, many rivulids exhibit a characteristic annual life cycle, with diapausing eggs and delayed embryonic development, which allows them to survive in the challenging seasonal ponds that they inhabit. Rivulidae also includes two species known as the only the self-fertilizing vertebrates and some species with internal fertilization. The first goal of this article is to review the systematics of the family considering phylogenetic relationships and synapomorphies of subfamilial clades, thus unifying information that is dispersed throughout the literature. From this revision, it is clear that phylogenetic relationships within Rivulidae are poorly resolved, especially in one of the large clades that compose it, the subfamily Rivulinae, where conflicting hypotheses of relationships of non-annual and annual genera are evident. The second goal of this work is to present an updated phylogenetic hypothesis (based on mitochondrial, nuclear, and morphological information) for one of the most speciose genus of Rivulidae, Austrolebias. Our results confirm the monophyly of the genus and of some subgeneric clades already diagnosed, but propose new relationships among them and their species composition, particularly in the subgenus Acrolebias.La familia Rivulidae es el cuarto clado más diverso dentro de los peces Neotropicales. Junto con algunos géneros de la familia Nothobranchiidae, muchos rivulidos presentan un característico ciclo de vida anual, con huevos resistentes a la desecación y embriones con diapausas que les permiten sobrevivir en los ambientes estacionales donde habitan. Los Rivulidae presentan también dos especies consideradas como los únicos vertebrados hermafroditas suficientes y algunas especies con inseminación interna. El primer objetivo de este artículo es actualizar la sistemática de la familia considerando las relaciones filogenéticas y las sinapomorfías de los clados que la componen, reuniendo información que se encuentra dispersa en la literatura. De esta revisión surge que las relaciones filogenéticas dentro de Rivulidae están todavía sin resolver, especialmente en uno de los grandes clados que la componen, la subfamilia Rivulinae, donde relaciones conflictivas entre géneros anuales y no anuales son evidentes. El segundo objetivo de este trabajo es presentar una hipótesis filogenética, basada en datos morfológicos, mitocondriales y nucleares, de uno de los géneros más diversos de la familia, el género Austrolebias. Nuestros resultados confirman la monofilia del género y de algunos clados subgenéricos previamente definidos, y propone nuevas relaciones entre ellos, particularmente de las especies del subgénero Acrolebias

    Evidencia de competencia por explotación entre parasitoides de huevos de Spodoptera frugiperda (Lepidoptera: Noctuidae) en el maíz

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    Telenomus remus and Trichogramma spp. (Hymenoptera: Platygastridae, Trichogrammatidae) are known egg parasitoids of the fall armyworm (FAW), Spodoptera frugiperda (Lepidoptera: Noctuidae) in Brazil. Parasitism of trichogrammatid on eggs of S. frugiperda has been relatively common, whereas the occurrence of T. remus in Brazilian crops has rarely been reported. Consequently, literature that gives insights about the interspecific competition among individuals of T. remus and Trichogramma spp. in the field is very scarce. Here we report the simultaneous occurrence of T. remus, Trichogramma pretiosum, and Tr. atopovirilia on eggs of the FAW in maize (Piracicaba, São Paulo, Brazil). Our findings imply that these three egg parasitoid species were engaged in exploitative competition (indirect interactions in which the depletion of resources by one species prevents the other access to them) toward eggs of S. frugiperda. Moreover, given the emergence of combinations of two and three of these parasitoid species from a single egg mass, our data strongly suggest that T. remus, Tr. pretiosum and Tr. atopovirilia were also engaged in interference competition (direct interactions among adults and/or immature individuals resulting in behavioral changes or even death of individuals). Both exploitative and interference competition may affect the population dynamics of parasitoids, with consequences for the biological control of pests. Hence, the present findings highlight the importance of determining the outcome of competition among T. remus, Tr. pretiosum and Tr. atopovirilia toward eggs of S. frugiperda in laboratory and field studies.Telenomus remus y Trichogramma spp. (Hymenoptera: Platygastridae, Trichogrammatidae) son parasitoides de huevos del gusano cogollero del maíz (GCM), Spodoptera frugiperda (Lepidoptera: Noctuidae) en Brasil. Mientras que los informes sobre el parasitismo de Trichogramma en huevos de S. frugiperda son relativamente comunes, los registros de T. remus en los cultivos brasileños son escasos. En consecuencia, la literatura sobre la competencia entre T. remus y Trichogramma spp. en campo es poca. En este trabajo, se presenta la presencia simultánea de T. remus, Trichogramma pretiosum y Tr. atopovirilia en huevos del GCM en el cultivo de maíz (Piracicaba, São Paulo, Brasil). Los resultados muestran que estas tres especies de parasitoides estuvieron involucradas en competencia exploratoria (interacción indirecta, donde el agotamiento de los recursos por parte de una especie impide que la otra tenga acceso a ellos) por los huevos de S. frugiperda. Sin embargo, teniendo en cuenta que se observó el surgimiento de dos y tres especies de parasitoides de una sola masa de huevos, los resultados sugieren que T. remus, Tr. pretiosum y Tr. atopovirilia también participaron en competencia por interferencia (interacciones directas entre los adultos y/o inmaduros que resultan en cambios en el comportamiento o muerte de los individuos). Ambos tipos de competencia pueden afectar la dinámica poblacional de parasitoides con consecuencias para el control biológico de plagas. Por consiguiente, nuestro trabajo destaca la importancia de investigar la competencia entre T. remus, Tr. pretiosum y Tr. atopovirilia por huevos de S. frugiperda en estudios de laboratorio y campo.Facultad de Ciencias Naturales y Muse

    Detection of invasive fish species with passive acoustics: Discriminating between native and non-indigenous sciaenids

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    Invasive alien species have been rising exponentially in the last decades impacting biodiversity and ecosystem functioning. The soniferous weakfish, Cynoscion regalis, is a recent invasive sciaenid species in the Iberian Peninsula and was first reported in the Tagus estuary in 2015. There is concern about its possible impacts on native species, namely the confamiliar meagre, Argyrosomus regius, as there is overlap in their feeding regime, habitat use, and breeding behaviour. Here, we characterised the sciaenid-like sounds recently recorded in the Tagus estuary and showed that they are made by weakfish as they have similar numbers of pulses and pulse periods to the sounds made by captive breeding weakfish. We further demonstrate that breeding grunts from weakfish and the native sciaenid, recorded either in captivity or Tagus estuary, differ markedly in sound duration, number of pulses and pulse period in the two species, but overlap in their spectral features. Importantly, these differences are easily detected through visual and aural inspections of the recordings, making acoustic recognition easy even for the non-trained person. We propose that passive acoustic monitoring can be a cost-effective tool for in situ mapping of weakfish outside its natural distribution and an invaluable tool for early detection and to monitor its expansion.Fundação para a Ciência e Tecnologia - FCTinfo:eu-repo/semantics/publishedVersio

    Effect of the aqueous extract of Ginkgo biloba L., Ginkgoaceae, in induced osteoporosis in Wistar rats

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    The objective of this study was to investigate the effect of a 20 day treatment with extract of Ginkgo biloba (EGb) in glucocorticoid-induced-osteoporosis. 36 rats were divided into six groups (n=6): control, osteoporosis, positive control, EGb1 (14 mg EGb/kg/day), EGb2 (28 mg EGb/kg/day) and EGb3 (56 mg EGb/kg/day). Treatments were conducted for twenty days, after osteoporosis was induced. Following euthanasia the femur and mandible of all animals were removed. The left mandible was radiographed to evaluate the cortical and the periodontal bone support (PBS). The histomorphometric analysis was performed on the right mandible and the right femur. The control group was compared with the osteoporosis group (Student's t-test). The other groups were analyzed through ANOVA test followed by Dunnett post-hoc test. There was a significantly reduction in the mesial PBS, in the percentage of the alveolar bone (PAB) of the mandible and percentage of the trabecular bone (PTB) of the femur in the osteoporosis group. There was an increase in the mesial PBS in the positive control group, EGb2 and EGb3. The PAB of the mandible and the PTB of the femur increased in the EGb2 and EGb3 groups. The EGb in the 28 mg/kg and 56 mg/kg doses were effective to increase the mesial PBS, the PAB of the mandible and the PTB of the femur.Este trabalho investigou os efeitos do tratamento por vinte dias com extrato de Ginkgo biloba (EGb) na osteoporose induzida por glicocorticóides. Foram utilizadas 36 ratas divididas em seis grupos (n=6): Controle, osteoporose, controle positivo, EGb1 (14 mg EGb/mg/kg/dia), EGb2 (28 mg EGb/kg/dia) e EGb3 (56 mg EGb/kg/dia). Os tratamentos foram realizados por vinte dias, após a indução da osteoporose. Após a eutanásia foram removidos o fêmur e a mandíbula de todos os animais. A mandíbula esquerda foi radiografada digitalmente para avaliação da cortical e do suporte ósseo periodontal (SOP). A análise histomorfométrica foi realizada no fêmur e mandíbula direitos. O grupo controle foi comparado ao grupo osteoporose (Teste t de Student) e os demais grupos foram submetidos a ANOVA, seguido do teste post-hoc de Dunnett. Houve redução significava do SOP mesial, percentual ósseo alveolar (POA) mandibular, percentual ósseo trabecular (POT) do fêmur no grupo osteoporose. Houve aumento do SOP mesial no grupo controle positivo, EGb2 e EGb3. O POA da mandíbula e o POT do fêmur aumentaram nos grupos EGb2 e EGb3. O EGb nas doses de 28 mg/kg e 56 mg/kg recuperou de forma significativa o SOP mesial, o POA da mandíbula e o POT do fêmur

    Cellular profile of the peritumoral inflammatory infiltrate in squamous cells carcinoma of oral mucosa: Correlation with the expression of Ki67 and histologic grading

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    <p>Abstract</p> <p>Background</p> <p>Squamous cells carcinoma is the most important malignant tumor with primary site in the oral cavity and, given the great exposure of mucosa and lips to the etiologic factors of this neoplasm, its incidence is high. Investigation of the prognostic determinants is significant for the expectations of treatment proposal and cure of the patient. The local immune response represented by peritumoral inflammatory infiltrate is a possible prognostic factor.</p> <p>Methods</p> <p>In this study, oral mucosa samples of squamous cells carcinoma were analyzed, separated according to their histological classification as well as the phenotypical profile of the cells comprising the peritumoral inflammatory infiltrate was investigated by immunohistochemical method, in addiction, the cell proliferation index via protein Ki67 expression was determinated.</p> <p>Results</p> <p>The T lymphocytes made up most of this inflammatory infiltrate, and among these cells, there was a predominance of T CD8 lymphocytes relative to the T CD4 lymphocytes. The B lymhocytes were the second most visualized leucocyte cell type followed by macrophages and neutrophils. The immunohistochemical assessment of Ki-67 positive cells revealed a greater expression of this protein in samples of undifferentiated squamous cells carcinoma.</p> <p>Conclusion</p> <p>The results suggest that the cellular immune response is the main defense mechanism in squamous cells carcinoma of oral mucosa, expressed by the large number of T lymphocytes and macrophages, and that the greatest intensity of local response may be associated with the best prognosis.</p

    The VISCACHA survey - I. Overview and first results

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    TheVISCACHA (VIsible Soar photometry of star Clusters in tApii and Coxi HuguA) Survey is an ongoing project based on deep photometric observations of Magellanic Cloud star clusters, collected using the SOuthern Astrophysical Research (SOAR) telescope together with the SOAR Adaptive Module Imager. Since 2015 more than 200 h of telescope time were used to observe about 130 stellar clusters, most of them with low mass (M < 104MΘ) and/or located in the outermost regions of the Large Magellanic Cloud and the Small Magellanic Cloud.With this high-quality data set, we homogeneously determine physical properties from statistical analysis of colour-magnitude diagrams, radial density profiles, luminosity functions, and mass functions. Ages, metallicities, reddening, distances, present-day masses, mass function slopes, and structural parameters for these clusters are derived and used as a proxy to investigate the interplay between the environment in theMagellanic Clouds and the evolution of such systems. In this first paper we present the VISCACHA Survey and its initial results, concerning the SMC clusters AM3, K37, HW20, and NGC 796 and the LMC ones KMHK228, OHSC3, SL576, SL61, and SL897, chosen to compose a representative subset of our cluster sample. The project's long-term goals and legacy to the community are also addressed.Fil: Maia, Francisco F. S.. Universidade de Sao Paulo; BrasilFil: Dias, Bruno. Universidad Andrés Bello; Chile. European Southern Observatory Santiago; ChileFil: Santos, Joao F. C.. Universidade Federal de Minas Gerais; BrasilFil: De Kerber, Leandro. Universidade de Sao Paulo; BrasilFil: Bica, Eduardo. Universidade Federal do Rio Grande do Sul; BrasilFil: Piatti, Andres Eduardo. Universidad Nacional de Córdoba. Observatorio Astronómico de Córdoba; Argentina. Consejo Nacional de Investigaciones Científicas y Técnicas; ArgentinaFil: Barbuy, Beatriz. Universidade de Sao Paulo; BrasilFil: Quint, Bruno. Gemini Observatory; ChileFil: Fraga, Luciano. Laboratório Nacional de Astrofísica; Brasil. Gemini Observatory; ChileFil: Sanmartim, David. Gemini Observatory; ChileFil: Angelo, Mateus S.. Centro Federal de Educação Tecnológica de Minas Gerais; BrasilFil: Hernandez-Jimenez, Jose A.. Universidade de Sao Paulo; BrasilFil: Santrich, Orlando J. Katime. Universidade Estadual de Santa Cruz; BrasilFil: Oliveira, Raphael A. P.. Universidade de Sao Paulo; BrasilFil: Pérez-Villegas, Angeles. Universidade de Sao Paulo; BrasilFil: Souza, Stefano O.. Universidade de Sao Paulo; BrasilFil: Vieira, Rodrigo G.. Universidade de Sao Paulo; BrasilFil: Westera, Pieter. Universidade Federal do ABC; Brasi
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