Grau de seletividade da escada de peixes do projeto experimental canal de migração da Itaipu Binacional

Orientador: Prof. Dr. Ângelo Antônio AgostinhoTese (doutorado) - Universidade Federal do Paraná, Setor de Ciências Biológicas, Curso de Pós-Graduação em Ciências BiológicasInclui referênciasÁrea de concentração: ZoologiaResumo: Foi pesquisado o grau de seletividade da escada de peixes, que compõe o projeto experimental Canal de migração de peixes da Itaipu Binacional, em relação à riqueza de espécies observadas no rio Paraná, bem como a variação diária na ascensão de peixes e os fatores ambientais relacionados. Para isso foram realizadas amostragens dos peixes que ascendem a dois pontos da escada (10m e 27m de desnível médio), durante 28 meses (novembro de 1994 a fevereiro de 1997), e quatro amostragens trimestrais realizadas no rio Paraná (março a dezembro de 1997), a jusante da escada de peixes. Amostragens nictemerais foram também realizadas na escada durante dois períodos de piracema (outubro de 1995 a fevereiro de 1996 e de novembro de 1996 a janeiro de 1997). Ao longo de todo o período amostrai, foram identificadas 31 espécies de peixes (4 exclusivas das amostragens nictemerais), sendo 19 characiformes e 12 siluriformes. Das 65 espécies registradas no rio imediatamente a jusante da barragem, 27 foram capturadas na escada. Entre as seis espécies mais abundantes na escada, quatro tiveram abundância moderada a jusante (Astyanax asuncionensis, Leporinus elongatus, Prochilodus lineatus, Pimelodus maculatus), uma foi esporádica (Leporinus friderici) e uma, de menor porte (Bryconamericus stramineus), não teve sua abundância avaliada em razão da seletividade dos aparelhos de pesca utilizados no rio. Por outro lado, duas espécies raras a jusante (Acestrorhynchus lacustris, Sorubim lima) apresentaram frequência e ocorrência moderada na escada. Entre as cinco espécies mais abundantes a jusante, apenas Schizodon borelli foi registrada na escada. As amostragens evidenciaram uma baixa seletividade específica ao longo da escada. Das 27 espécies que nela ingressaram, 22 foram registradas a 10 metros de desnível, e 24 a 27m. Embora as capturas nos dois trechos amostrados da escada tenham revelado coincidência entre as espécies mais abundantes, a ascensão dos peixes ao topo da escada foi mais sazonal. O número total de exemplares foi inferior neste trecho (814 a 10 metros e 647 a 27 metros). A escada apresentou uma seleção negativa aos grandes pimelodídeos migradores que pode ser superada com a ampliação na escala de seu projeto. Seu modelo hidráulico mostrou-se, de maneira geral, eficiente na atração e, principalmente, na ascensão de peixes. Nas amostragens nictemerais, realizadas para avaliar os efeitos do horário do dia, fase de reprodução e tamanho dos indivíduos na ascensão de peixes da escada, foram registradas 22 espécies, sendo que 90,4% dos exemplares pertenceram às espécies Prochilodus lineatus, Pimelodus maculatus, Leporinus elongatus, Schizodon borelli, Leporinus friderici e Astyanax asuncionensis. O tamanho dos indivíduos, para as três primeiras espécies, mais frequentes e tidas como grandes migradoras, não diferiu significativamente entre os dois trechos da escada e os horários considerados. Para S. borelli indivíduos menores foram registrados, em ambos os trechos, às 20:00h. Já para L. friderici foi detectada uma interação significativa entre horário de coleta e ponto amostrado. Entre as espécies mais frequentes, a habilidade de ascender à escada não mostrou relação com a migração reprodutiva, constatando-se um predomínio significativo de fases gonadais pré-vitelogênicas para todas as espécies e em todos os horários do dia, exceto entre A. asuncionensis capturados no topo da escada, às 2:00hs. Destas espécies, apenas as duas de Leporinus são mais abundantes no topo da escada durante o dia. Para o conjunto das espécies capturadas, aquelas da Ordem Siluriformes tem ascensão predominantemente noturna. Para a análise da sazonalidade na ascensão de peixes na escada experimental e avaliação das relações com a reprodução, temperatura, nível do rio e suas vazões, modelos autoregressivos foram empregados com o objetivo de remover a dependência temporal entre as observações, sendo utilizados os resíduos dos modelos para relacionar, através do coeficiente de Pearson, as densidades de peixes com as variáveis ambientais. Padrões claros de sazonalidade foram observados para a variável temperatura. As variáveis cota do rio, vazão turbinada (água que passa pelas unidades geradoras) e vazão vertida (água que passa pelo vertedouro), embora não tenham apresentado dinâmicas sazonais claras, foram temporalmente dependentes. Constatou-se, para as 23 espécies de porte médio e grande, uma marcante sazonalidade, com os maiores valores de abundância registrados sistematicamente nos meses de outubro a fevereiro (75%). O padrão temporal registrado para as espécies de pequeno porte, com predomínio de Bryconamericus stramineus, mostrou-se distinto entre os dois anos analisados. Sob condições de vazão e velocidade constante na escada, verificou-se influências significativas da temperatura da água e da vazão turbinada pela Hidrelétrica de Itaipu sobre a intensidade de ascensão dos peixes. A vazão vertida e o nível do rio não mostraram influências relevantes, em parte devido à posição do vertedouro (1000m a jusante) em relação à escada. O modelo hidráulico da escada para peixes do projeto experimental Canal de Migração de Peixes da Itaipu Binacional revelou-se promissor na atração e ascensão de peixes do rio Paraná, especialmente para espécies migradoras characiformes e siluriformes, sendo passível de utilização prática em barragens da Bacia. Cabe, entretanto, ressaltar que as escadas de peixes não se constituem em solução aplicável a todos os problemas gerados pelos represamentos às populações de peixes migradores neotropicais, visto que a capacidade de continuar o processo migratório, a localização dos locais de desova e a capacidade de retomar aos trechos a jusante são, também, de alta relevância. Devido às características do ciclo de vida destas espécies, as escadas seriam recursos válidos para assegurar a heterogeneidade genética dos estoques a montante, através do restabelecimento do contato de sub-populações isoladas pelo represamento (Agostinho et al, subm.). Isto, entretanto, só será efetivo quando trechos relevantes do rio a montante permanecerem livres e preservados.Abstract: This study investigates the selectivity of the experimental Migration Channel project of Itaipu Binacional, in relation to the wealth of species observed in the Paraná River, as well as the daily variation in the ascent of fishes and the related environmental factors. For this purpose, samples were taken of the ascending fishes at two points of the ladder (10 and 27 meters of mean height), during 28 months (November of 1994 to February of 1997), and in every quarter four samplings were carried out in the Paraná River, below the fish ladder, in 1997. During two periods of fish migration (October of 1995 to February of 1996 and from November of 1996 to January of 1997), monthly night-time samplings were made. In the course of the entire sampling period, 31 fish species were identified (4 of them exclusive to the night-time sampling), with 19 characiforms and 12 siluriformes. Of the 65 species recorded in the river immediately downstream from the dam, 27 were captured on the ladder. Among the six most abundant species on the ladder, four were moderately abundant downstream (Astyanax asuncionensis, Leporinus elongatus, Prochilodus lineatus, Pimelodus maculatus), one was sporadic (Leporinus friderici) and one, of lesser size (Bryconamericus stramineus), could not be evaluated due to the selectivity of the fishing tackle employed in the river. On the other hand, two species that are rare downstream (Acestrorhynchus lacustris, Sorubim lima) presented a moderate frequency and occurrence on the ladder. Among the five most abundant downstream species, only Schizodon borelli was recorded on the ladder. The samplings demonstrated a low specific selectivity along the length of the ladder. Of the 27 species that entered the ladder, 22 were recorded at the 10 metres height, and 24 at the 27 m level. Although the catches in the two ladder stretches that were sampled revealed a coincidence among the most abundant species, the ascent of fishes to the top of the ladder was more seasonal. The number of individuals was also inferior in this stretch (814 at 10 metres and 647 at 27 metres). The ladder presented negative selectivity with regard to the large migratory pimelodideans which can be corrected by enlarging the scale of its design. Its hydraulic design proved to be, in general, efficient in the attraction and, principally, in the ascent of fishes. In the night-time samplings, carried out to evaluate the effects of the time of day, reproductive phase and size of the individuals in the ascent of fishes up the ladder, 22 species were recorded, of which 90,4% of the samples pertained to the species Prochilodus lineatus, Pimelodus maculatus, Leporinus elongatus, Schizodon borelli, Leporinus friderici and Astyanax asuncionensis. The size of the individuals in the three first species, more frequent and considered to be great migrants, did not differ consistently between the two stretches of the ladder and the timetables considered. For S. borelli, smaller individuals were recorded between both stretches of the ladder and the timetables considered. Regarding L. frederici an important interaction was detected between the hour of the sampling and the point sampled. Among the most frequent species the ability to ascend the ladder was not related to the reproductive migration, with a significant predominance of previtellinogenic gonads being verified for all species and at all hours of the day, except among the A. asuncionensis captured at the top of the ladder at 2:00 hours. Of these species only the two Leporinus are more abundant at the top of the ladder during the day. Among all the species taken, those of the Siluriformes Order make their ascent predominantly during the night. For the analysis of the ascent of fishes up the experimental ladder and the evaluation of the relationships with reproduction, temperature, water level and flows, autoregressive models were employed with the objective of removing the time-dependence between the observations, with the residues of the models being used to link, by means of the Pearson coefficient, the fish densities with the environmental variables. Clear standards of seasonality were observed for the temperature variable. The variables of river elevation, flow through the turbines and through the spillway, although not presenting clear seasonal dynamics, were time-dependent. For the 23 species of medium and large size, a marked seasonality was verified, with the greatest figures of abundance systematically recorded in the months of October to February (75%). The time frame recorded for the small sized species, with a predominance of Bryconamericus stramineus, differed between the two years that were analysed. Under conditions of constant flow and velocity in the ladder, significant influences were exerted upon the intensity of the ascent of fishes by the temperature of the water and its flow through the turbines of the Itaipu Hydroelectric power plant. The spilled flow and the river level did not demonstrate relevant influences, partly due to the location of the spillway (1,000 m downstream) in relation to the ladder. The hydraulic model of the experimental Fish Migration Channel project of Itaipu Binacional showed promise in the attraction and ascent of the fishes of the Paraná River, especially regarding the characiforms and siluriformes migratory species, proving its feasibility for practical application in the dams of the Basin. It is necessary, however, to point out that fish ladders do not constitute a solution applicable to all the problems presented by the impoundment of subtropical migratory fish populations. Considered the capacity to continue the migratory process, the location of spawning areas and the capability to come back to downstream areas, have also a great importance. Due to the characteristics of the life cycle of these fishes, the ladders would be valid resources to assure the genetic heterogeneity of the upstream stocks, by re-establishing the contact between the subpopulations isolated by the impoundment (Agostinho et al, subm.). This, however, is only effective when relevant upstream stretches of the river remain free and are preserved

Supplementation with high-content docosahexaenoic acid triglyceride in attention-deficit hyperactivity disorder: a randomized double-blind placebo-controlled trial.

Background: Attention-deficit hyperactivity disorder (ADHD) is a complex disorder in terms of etiology, clinical presentation, and treatment outcome. Pharmacological and psychological interventions are recommended as primary treatments in ADHD; however, other nonpharmacological intervention such as a dietary supplementation with omega-3 polyunsaturated fatty acids (ω-3 PUFAs) has emerged as an attractive option. Purpose: The objective of the present study was to assess whether dietary supplementation with highly concentrated ω-3 docosahexaenoic acid (DHA) triglyceride may improve symptoms in ADHD. Method: A 6-month prospective double-blind placebo-controlled randomized clinical trial was designed in 66 patients with ADHD, aged between 6 and 18 years. Participants in the experimental group received a combination of ω-3 fatty acids (DHA 1,000 mg, eicosapentaenoic acid 90 mg, and docosapentaenoic acid 150 mg). Instruments included d2-test, AULA Nesplora, EDAH scales, and abbreviated Conner's Rating Scale. Results: In the cognitive test, between-group differences were not found, but within-group differences were of a greater magnitude in the DHA group. Between-group differences in favor of the DHA arm were observed in behavioral measures, which were already detected after 3 months of treatment. Results were not changed when adjusted by ADHD medication. Conclusions: This study provides further evidence of the beneficial effect of supplementation with ω-3 DHA in the management of ADHD

Use of autoantigen-loaded phosphatidylserine-liposomes to arrest autoimmunity in type 1 diabetes

INTRODUCTION: The development of new therapies to induce self-tolerance has been an important medical health challenge in type 1 diabetes. An ideal immunotherapy should inhibit the autoimmune attack, avoid systemic side effects and allow β-cell regeneration. Based on the immunomodulatory effects of apoptosis, we hypothesized that apoptotic mimicry can help to restore tolerance lost in autoimmune diabetes. OBJECTIVE: To generate a synthetic antigen-specific immunotherapy based on apoptosis features to specifically reestablish tolerance to β-cells in type 1 diabetes. METHODS: A central event on the surface of apoptotic cells is the exposure of phosphatidylserine, which provides the main signal for efferocytosis. Therefore, phosphatidylserine-liposomes loaded with insulin peptides were generated to simulate apoptotic cells recognition by antigen presenting cells. The effect of antigen-specific phosphatidylserine-liposomes in the reestablishment of peripheral tolerance was assessed in NOD mice, the spontaneous model of autoimmune diabetes. MHC class II-peptide tetramers were used to analyze the T cell specific response after treatment with phosphatidylserine-liposomes loaded with peptides. RESULTS: We have shown that phosphatidylserine-liposomes loaded with insulin peptides induce tolerogenic dendritic cells and impair autoreactive T cell proliferation. When administered to NOD mice, liposome signal was detected in the pancreas and draining lymph nodes. This immunotherapy arrests the autoimmune aggression, reduces the severity of insulitis and prevents type 1 diabetes by apoptotic mimicry. MHC class II tetramer analysis showed that peptide-loaded phosphatidylserine-liposomes expand antigen-specific CD4+ T cells in vivo. The administration of phosphatidylserine-free liposomes emphasizes the importance of phosphatidylserine in the modulation of antigen-specific CD4+ T cell expansion. CONCLUSIONS: We conclude that this innovative immunotherapy based on the use of liposomes constitutes a promising strategy for autoimmune diseases

Use of Autoantigen-Loaded Phosphatidylserine-Liposomes to Arrest Autoimmunity in Type 1 Diabetes

Introduction: The development of new therapies to induce self-tolerance has been an important medical health challenge in type 1 diabetes. An ideal immunotherapy should inhibit the autoimmune attack, avoid systemic side effects and allow a-cell regeneration. Based on the immunomodulatory effects of apoptosis, we hypothesized that apoptotic mimicry can help to restore tolerance lost in autoimmune diabetes. Objective: To generate a synthetic antigen-specific immunotherapy based on apoptosis features to specifically reestablish tolerance to a-cells in type 1 diabetes. Methods: A central event on the surface of apoptotic cells is the exposure of phosphatidylserine, which provides the main signal for efferocytosis. Therefore, phosphatidylserine-liposomes loaded with insulin peptides were generated to simulate apoptotic cells recognition by antigen presenting cells. The effect of antigen-specific phosphatidylserine-liposomes in the reestablishment of peripheral tolerance was assessed in NOD mice, the spontaneous model of autoimmune diabetes. MHC class II-peptide tetramers were used to analyze the T cell specific response after treatment with phosphatidylserine-liposomes loaded with peptides. Results: We have shown that phosphatidylserine-liposomes loaded with insulin peptides induce tolerogenic dendritic cells and impair autoreactive T cell proliferation. When administered to NOD mice, liposome signal was detected in the pancreas and draining lymph nodes. This immunotherapy arrests the autoimmune aggression, reduces the severity of insulitis and prevents type 1 diabetes by apoptotic mimicry. MHC class II tetramer analysis showed that peptide-loaded phosphatidylserine-liposomes expand antigen-specific CD4+ T cells in vivo. The administration of phosphatidylserine-free liposomes emphasizes the importance of phosphatidylserine in the modulation of antigen-specific CD4+ T cell expansion. Conclusions: We conclude that this innovative immunotherapy based on the use of liposomes constitutes a promising strategy for autoimmune diseases.This work was supported by a grant from Spanish Government (FIS PI12/00195). IPA was supported by AGAUR, Generalitat de Catalunya. MVP and RA are supported by the Health Dept. of the Catalan Government, Generalitat de Catalunya. Special thanks to Ms. M.A. Cardus and her family for their generous donatio

Current professional standing of young medical oncologists in Spain : a nationwide survey by the Spanish Society of Medical Oncology + MIR section

There is a lack of knowledge about the career paths and employment situation of young medical oncologists. The aim of our study was to evaluate the current professional standing of these professionals in Spain. The Spanish Society of Medical Oncology + MIR section conducted a national online survey in May 2021 of young medical oncology consultants (< 6 years of expertise) and final year medical oncology residents. A total of 162 responses were eligible for analysis and included participants from 16 autonomous communities; 64% were women, 80% were consultants, and 20% were residents. More than half of the participants performed routine healthcare activity and only 7% research activity. Almost three quarters (73%) were subspecialized in a main area of interest and almost half of these chose this area because it was the only option available after residency. Half of the respondents (51%) considered working abroad and 81% believed the professional standing in Spain was worse than in other countries. After finishing their residency, only 22 were offered a job at their training hospital. Just 16% of participants had a permanent employment contract and 87% were concerned (score of ≥ 5 on a scale of 1-10) about their job stability. In addition, one quarter of the participants in our study showed an interest in increasing their research activity. The choice of subspecialty in medical oncology may depend on job opportunities after residency rather than personal interest. The abundance of temporary contracts may have influenced the job stability concerns observed. Future mentoring strategies should engage in building a long-term career path for young medical oncologists. The online version contains supplementary material available at 10.1007/s12094-022-02989-3

Gene-environment interaction analysis of redox-related metals and genetic variants with plasma metabolic patterns in a general population from Spain: The Hortega Study

Background: Limited studies have evaluated the joint influence of redox-related metals and genetic variation on metabolic pathways. We analyzed the association of 11 metals with metabolic patterns, and the interacting role of candidate genetic variants, in 1145 participants from the Hortega Study, a population-based sample from Spain. Methods: Urine antimony (Sb), arsenic, barium (Ba), cadmium (Cd), chromium (Cr), cobalt (Co), molybdenum (Mo) and vanadium (V), and plasma copper (Cu), selenium (Se) and zinc (Zn) were measured by ICP-MS and AAS, respectively. We summarized 54 plasma metabolites, measured with targeted NMR, by estimating metabolic principal components (mPC). Redox-related SNPs (N = 291) were measured by oligo-ligation assay. Results: In our study, the association with metabolic principal component (mPC) 1 (reflecting non-essential and essential amino acids, including branched chain, and bacterial co-metabolism versus fatty acids and VLDL subclasses) was positive for Se and Zn, but inverse for Cu, arsenobetaine-corrected arsenic (As) and Sb. The association with mPC2 (reflecting essential amino acids, including aromatic, and bacterial co-metabolism) was inverse for Se, Zn and Cd. The association with mPC3 (reflecting LDL subclasses) was positive for Cu, Se and Zn, but inverse for Co. The association for mPC4 (reflecting HDL subclasses) was positive for Sb, but inverse for plasma Zn. These associations were mainly driven by Cu and Sb for mPC1; Se, Zn and Cd for mPC2; Co, Se and Zn for mPC3; and Zn for mPC4. The most SNP-metal interacting genes were NOX1, GSR, GCLC, AGT and REN. Co and Zn showed the highest number of interactions with genetic variants associated to enriched endocrine, cardiovascular and neurological pathways. Conclusions: Exposures to Co, Cu, Se, Zn, As, Cd and Sb were associated with several metabolic patterns involved in chronic disease. Carriers of redox-related variants may have differential susceptibility to metabolic alterations associated to excessive exposure to metals.This work was supported by the Strategic Action for Research in Health sciences [CP12/03080, PI15/00071, PI10/0082, PI13/01848, PI14/00874, PI16/01402, PI21/00506 and PI11/00726], CIBER Fisio patología Obesidad y Nutrición (CIBEROBN) (CIBER-02-08-2009, CB06/03 and CB12/03/30,016), the State Agency for Research (PID2019-108973RB- C21 and C22), the Valencia Government (GRUPOS 03/101; PROMETEO/2009/029 and ACOMP/2013/039, IDI FEDER/2021/072 and GRISOLIAP/2021/119), the Castilla-Leon Government (GRS/279/A/08) and European Network of Excellence Ingenious Hypercare (EPSS-037093) from the European Commission. The Strategic Action for Research in Health sciences, CIBERDEM and CIBEROBN are initiatives from Carlos III Health Institute Madrid and cofunded with European Funds for Regional Development (FEDER). The State Agency for Research and Carlos III Health Institute belong to the Spanish Ministry of Science and Innovation. ADR received the support of a fellowship from “la Caixa” Foundation (ID 100010434) (fellowship code “LCF/BQ/DR19/11740016”). MGP received the support of a fellowship from “la Caixa” Foundation (ID 100010434, fellowship code LCFLCF/BQ/DI18/11660001). The funding bodies had no role in the design of the study and collection, analysis, and interpretation of data and in writing the manuscript.S

Cosmic-ray energy densities in star-forming galaxies

The energy density of cosmic ray protons in star forming galaxies can be estimated from π0-decay γ-ray emission, synchrotron radio emission, and supernova rates. To galaxies for which these methods can be applied, the three methods yield consistent energy densities ranging from Up ~ 0.1 − 1 eV cm−3 to Up ~ 102 − 103 eV cm−3 in galaxies with low to high star-formation rates, respectively