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2.
Int J Sports Med ; 41(1): 21-26, 2020 Jan.
Artigo em Inglês | MEDLINE | ID: mdl-31756737

RESUMO

The aim of the study was to verify the relative contributions of energetic and kinematic parameters to the performance in 400-m front crawl test. Fourteen middle-distance swimmers participated in the study. Oxygen consumption was measured directly and blood samples were collected to assay lactate concentration. Both oxygen consumption and lactate concentration were used to calculate the: (i) overall energy expenditure, (ii) anaerobic (alactic and lactic) and (iii) aerobic contributions. The mean centre of mass speed and intracycle velocity variation were determined through three-dimensional kinematic analysis. Mean completion time was 315.64±26.91s. Energetic contributions were as follows: 6.1±0.28% from alactic anaerobic metabolism, 5.9±0.63% from anaerobic lactic and 87.8±0.88% from aerobic. Mean intracycle velocity variation was 0.14±0.03. The results indicated that performance of 400-m test relies predominantly on aerobic power. Parameters such as lactate, mean speed, anaerobic lactic and alactic (kW) correlated with performance of 400-m test (p <0.05). Multiple linear regressions indicated that mean centre of mass speed and anaerobic alactic (kW) determined the 400-m test performance (R2=0.92). Even though the T400 is characterized by aerobic metabolism, the anaerobic alactic component cannot be negligible at this competition level.


Assuntos
Metabolismo Energético/fisiologia , Teste de Esforço/métodos , Natação/fisiologia , Fenômenos Biomecânicos/fisiologia , Comportamento Competitivo/fisiologia , Humanos , Ácido Láctico/sangue , Masculino , Oxigênio/sangue , Consumo de Oxigênio , Estudos de Tempo e Movimento , Gravação em Vídeo , Adulto Jovem
3.
Biosci Biotechnol Biochem ; 84(1): 159-170, 2020 Jan.
Artigo em Inglês | MEDLINE | ID: mdl-31483212

RESUMO

We tested whether Sake Lees (SL) had inhibitory effects on hyperalgesia in the hindpaw under psychophysical stress conditions. Male rats were subjected to repeated forced swim stress treatments (FST) from Day -3 to Day -1. Intraperiotoneal administration of SL which contained low concentration of ethanol (SLX) was conducted after each FST. On Day 0, formalin-evoked licking behaviors and Fos responses in the lumbar spinal cord (DH) and several areas within the rostral ventromedial medulla (RVM) were quantified as nociceptive responses. FST-induced hyperalgesia in the hindpaw was prevented by repeated SL and SLX treatments. Fos expression was significantly increased in DH and some areas within the RVM under FST, which was prevented by repeated SL or SLX. These findings indicated that daily administration of SL had the potential to alleviate stress-induced hyperalgesia.


Assuntos
Fermentação , Membro Posterior/metabolismo , Hiperalgesia/tratamento farmacológico , Oryza/química , Extratos Vegetais/farmacologia , Proteínas Proto-Oncogênicas c-fos/metabolismo , Corno Dorsal da Medula Espinal/metabolismo , Estresse Fisiológico/fisiologia , Animais , Comportamento Animal/efeitos dos fármacos , Etanol/química , Formaldeído/administração & dosagem , Formaldeído/farmacologia , Hiperalgesia/etiologia , Imuno-Histoquímica , Masculino , Manejo da Dor , Medição da Dor , Extratos Vegetais/administração & dosagem , Proteínas Proto-Oncogênicas c-fos/imunologia , Ratos , Ratos Sprague-Dawley , Neurônios Serotoninérgicos/efeitos dos fármacos , Neurônios Serotoninérgicos/metabolismo , Serotonina/imunologia , Serotonina/metabolismo , Natação/fisiologia , Distribuição Tecidual
4.
Chemosphere ; 240: 124917, 2020 Feb.
Artigo em Inglês | MEDLINE | ID: mdl-31726617

RESUMO

With the pressure to ban or limit the use of Bisphenol A (BPA), substitutes such as bisphenol F (BPF) are applied to various commodities and generally detected in aquatic systems worldwide. To understand the potential ecological risk of BPF, the acute toxicity as well as behavioural, physiological and biochemical parameters of the water flea Daphnia magna were assessed. Following BPF exposure at concentrations ranging from 0.1 µg L-1 to 100 µg L-1, phenotypic traits including growth development, fecundity and swimming activity were significantly inhibited in response to exposure to sublethal concentrations (1-100 µg L-1) of BPF, which had a positive relationship with the activity of antioxidant enzymes. Moreover, the acetylcholinesterase (AChE) activity, which was strictly associated with the behavioural changes, was clearly inhibited, which was also obviously related to the heart rate and thoracic limb activity. Compared to the toxicity of BPA, BPF induces similar toxic effects, and the health concerns regarding the use of these alternatives should be highlighted.


Assuntos
Compostos Benzidrílicos/toxicidade , Daphnia/efeitos dos fármacos , Fenóis/toxicidade , Poluentes Químicos da Água/toxicidade , Animais , Antioxidantes/metabolismo , Daphnia/enzimologia , Relação Dose-Resposta a Droga , Ecotoxicologia , Fertilidade/efeitos dos fármacos , Natação , Testes de Toxicidade
5.
Food Chem ; 308: 125607, 2020 Mar 05.
Artigo em Inglês | MEDLINE | ID: mdl-31677599

RESUMO

Lipid sources as alternatives to fish oil could alter the nutritional value and flavor quality of crab meat affecting consumer preferences. Herein, an 8-week nutritional trial was designed to investigate the effects of dietary lipid sources including fish oil (FO), krill oil (KO), palm oil, rapeseed oil, soybean oil and linseed oil on profiles of amino acids, fatty acids and volatiles in muscle of swimming crab (Portunus trituberculatus). Volatiles of crab muscle were characterized by headspace solid-phase microextraction and gas chromatography-tandem mass spectrometry. Results revealed that crabs fed FO and KO had significantly higher levels of protein, indispensable amino acids, eicosapentaenoic acid and docosahexaenoic acid in muscle. Principal component analysis and hierarchical cluster analysis demonstrated that muscle volatiles of crabs fed different dietary oils exhibited significant variations. Dietary FO and KO significantly increased the relative levels of 3-methylbutanal, heptanal, benzaldehyde and nonanal in muscle, which may produce more pleasant flavors.


Assuntos
Braquiúros/química , Aromatizantes/análise , Animais , Gorduras na Dieta/análise , Ácidos Docosa-Hexaenoicos/análise , Ácido Eicosapentaenoico/análogos & derivados , Ácido Eicosapentaenoico/análise , Ácidos Graxos/análise , Cromatografia Gasosa-Espectrometria de Massas/métodos , Estado Nutricional , Valor Nutritivo , Alimentos Marinhos/análise , Microextração em Fase Sólida , Natação , Paladar
6.
Ying Yong Sheng Tai Xue Bao ; 30(12): 4344-4352, 2019 Dec.
Artigo em Chinês | MEDLINE | ID: mdl-31840481

RESUMO

Behavioral and physiological ecology are two important research aspects of ecological field. Related studies help us better understand the marine animal's habit and adaptability to environment. Antarctic krill (Euphausia superba, thereafter krill) is a key-stone species in the Southern Ocean. Understanding its behavioral and physiological ecology can understand the ability of marine organisms such as krill to cope with extreme environment. We summarized the typical ecological characteristics of krill from both aspects of behavioral ecology and physiological ecology. Behavioral ecology included its swarming (size and behavior) and swimming (angle, beat of pleopod), while physiological ecology included respiration, excretion, metabolism, molting and growth. Generally, the studies on behavioral and physiological ecology of krill were very limited, and many studies were based on land-based krill aquarium. In view of the large difference between land-based aquarium and natural environment of krill, it's extremely urgent to develop the in-situ experimental ecology of krill in the sea.


Assuntos
Euphausiacea , Animais , Regiões Antárticas , Ecologia , Meio Ambiente , Natação
7.
Zoolog Sci ; 36(6): 511-520, 2019 Dec 09.
Artigo em Inglês | MEDLINE | ID: mdl-31833322

RESUMO

To gain a better understanding of the effect of reproductive modes and swimming ability on ostracod distribution, we visited 111 randomly selected aquatic sites in Kirsehir province. A total of 35 ostracods were newly reported for the area. The number of species with and without swimming setae was not statistically different, but numbers of sexual species was significantly lower than parthenogenetics. Species without setae did not show a significant difference between sexual and parthenogenetic forms. Numbers of species with (out) setae were not significant among different elevational ranges. Distribution of parthenogenetic species was common in all 11 habitat types when sexual species were only found from three different types located from 690 to ca. 1400 m of elevational ranges. Numbers of parthenogenetic species with or without setae did not show a difference among the ranges, but sexual species without setae exhibited wider distributional ranges (690-1289 m) than species with swimming setae (690-1089 m). Species' co-occurrence revealed two positive, five negative, and 44 random pairs of co-occurrences. Wards cluster analyses portrayed three main clustering groups. While group I includes parthenogenetic and sexual species, group II covers mostly parthenogenetic species with and without setae. Group III consists of species without setae. CCA results displayed three environmental variables (water temperature, pH and elevation) effective on species distribution. Species distributed in all elevational ranges tend to show lower optimum and wider ecological tolerances. Parthenogenetic species with swimming setae and with relatively higher tolerance ranges were dominant over sexual species. The present results suggest that swimming mode has a greater effect on species distribution among the habitats than reproductive modes.


Assuntos
Crustáceos/fisiologia , Ecossistema , Natação/fisiologia , Distribuição Animal , Animais , Reprodução/fisiologia , Especificidade da Espécie , Turquia
8.
Br Dent J ; 227(12): 1011, 2019 12.
Artigo em Inglês | MEDLINE | ID: mdl-31873235
9.
Sci Total Environ ; 695: 133913, 2019 Dec 10.
Artigo em Inglês | MEDLINE | ID: mdl-31756843

RESUMO

The majority of reports on the toxic effect of cyanobacterial metabolites on the freshwater invertebrates is based on determination of two endpoints: mortality or immobilization. However, detection of sub-lethal effects requires more sensitive indicators The aim of the present study was to evaluate the applicability of digital-video analysis for determination of early behavioral and physiological responses in the assessment of effects caused by the cyanobacterial neurotoxin, anatoxin-a (ANTX) at a broad range of its concentration (0.5-50 µg/mL). Swimming speed (SS), heart rate (HR), oxygen consumption (OC), thoracic limb activity (TLA) and abdominal claw movement (ACM) of Daphnia magna were evaluated. Swimming speed and abdominal claw movements were determined by digital analysis of video clips by Tracker® software; OC by Oxygraph Plus System® while HR, TLA and ACM by digital frame-by-frame analysis of video clips of microscopic view with the use of a media player software. The experimental study showed a concentration- and time-dependent decrease of SS, HR, OC, TLA and ACM. SS was inhibited as early as after 10 s of the exposure of Daphnia magna to ANTX, and the other physiological responses after 2 h. Further inhibition of these parameters was also noted after 24 h of the exposure. On the other hand, stimulation of ACM was noted at the lower (0.5 and 2.5 µg/mL) ANTX concentrations after both 2 h and 24 h of exposure. The results indicated that some behavioral and physiological biomarkers measured by video analysis may be a valuable tool for an early determination of toxic effects induced by cyanobacterial metabolites in zooplankters.


Assuntos
Daphnia/fisiologia , Tropanos/toxicidade , Poluentes Químicos da Água/toxicidade , Animais , Cianobactérias , Água Doce , Natação , Testes de Toxicidade
10.
Phys Rev Lett ; 123(13): 138003, 2019 Sep 27.
Artigo em Inglês | MEDLINE | ID: mdl-31697550

RESUMO

We study the orientation statistics of spheroidal, axisymmetric microswimmers, with shapes ranging from disks to rods, swimming in chaotic, moderately turbulent flows. Numerical simulations show that rodlike active particles preferentially align with the flow velocity. To explain the underlying mechanism, we solve a statistical model via the perturbation theory. We show that such an alignment is caused by correlations of fluid velocity and its gradients along particle paths combined with fore-aft symmetry breaking due to both swimming and particle nonsphericity. Remarkably, the discovered alignment is found to be a robust kinematical effect, independent of the underlying flow evolution. We discuss its possible relevance for aquatic ecology.


Assuntos
Modelos Teóricos , Fenômenos Fisiológicos Bacterianos , Fenômenos Biomecânicos , Hidrodinâmica , Modelos Biológicos , Movimento (Física) , Natação
11.
Phys Rev Lett ; 123(15): 158006, 2019 Oct 11.
Artigo em Inglês | MEDLINE | ID: mdl-31702312

RESUMO

Microswimmers in nature often experience spatial gradients of viscosity. In this Letter we develop theoretical results for the dynamics of active particles, biological or otherwise, swimming through viscosity gradients. We model the active particles using the squirmer model, and show how viscosity gradients lead to viscotaxis for squirmers, and how the effects of viscosity gradients depend on the swimming gait of the microswimmers. We also show how such gradients in viscosity can be used to control active particles and suggest a mechanism to sort them based on their swimming style.


Assuntos
Modelos Teóricos , Chlamydomonas/fisiologia , Escherichia coli/fisiologia , Modelos Biológicos , Modelos Químicos , Natação , Viscosidade
12.
J Sports Med Phys Fitness ; 59(10): 1709-1715, 2019 Oct.
Artigo em Inglês | MEDLINE | ID: mdl-31694363

RESUMO

BACKGROUND: The purpose of this study was to investigate the effects of an Ironman-distance triathlon on bone metabolism. METHODS: Nine recreational male triathletes (39.7±8.2 years old) were voluntarily recruited before a 226-km Ironman triathlon race. Baseline blood samples were collected >1 hour before race. Serial post-race blood sampling time points included immediately (0hr), 1 hour (1hr), 1 day (d), 3 d, and 5 d after the Ironman race. RESULTS: Serum muscle damage markers, serum myoglobin, creatine kinase (CK) and lactate dehydrogenase (LDH) revealed significant post-race peak values immediately, 1hr and 1d after the race, respectively. Except for the marginally higher serum CK and myoglobin at 5d (P=0.01~0.05), all post-race serum levels of muscle damage markers were significantly higher than baseline levels (P<0.01). Serum phosphorus values were significantly higher immediately (0hr) after the Ironman race. Serum osteocalcin, an index specific to bone formation, showed a significant decrease at time points 0hr and 1hr, but a significant increase 1 day after (P<0.01) and a marginal increase 3 and 5 days after (P=0.01~0.05) the race. No difference was shown in type I collagen C-telopeptide (CTX-1), a bone resorption marker. Pearson's correlation between serum osteocalcin and CTX-1 was done at each time point, and significant correlation was shown on the 5th d after the race (r=0.591, P<0.05). CONCLUSIONS: An Ironman-distance contest induces a bone-formative-favoring turnover during the post-race period for amateur male triathletes.


Assuntos
Desempenho Atlético , Osso e Ossos/metabolismo , Adulto , Atletas , Ciclismo/fisiologia , Biomarcadores/análise , Creatina Quinase/sangue , Humanos , L-Lactato Desidrogenase/sangue , Masculino , Pessoa de Meia-Idade , Mioglobina/sangue , Resistência Física/fisiologia , Corrida/fisiologia , Natação/fisiologia
13.
Undersea Hyperb Med ; 46(5): 581-601, 2019.
Artigo em Inglês | MEDLINE | ID: mdl-31683356

RESUMO

Introduction: We aimed to document identified cases of immersion pulmonary edema (IPE) in divers from Oceania (the Indo-Pacific region) from January 2002 to May 2018, inclusive. Method: Cases were identified using various sources, including searches of the Divers Alert Network Asia-Pacific (DAN AP) Fatality Database, published case reports, and interviews with survivors who had reported their incident to DAN AP. Where available, investigations, pathology and autopsy results were obtained. Only incidents diagnosed as IPE by diving physicians or pathologists with experience in the investigation of diving accidents were included. Individual case histories and outcomes, together with brief individual summaries of the associations and possible contributing factors were recorded. Results: Thirty-one IPE incidents in divers from Oceania were documented. There were two surface snorkelers, 22 scuba air divers and seven nitrox divers which included three closed-circuit rebreathers (CCR). The mean (SD) age was 53 (12) years, 58% of victims were females, and the average dive profile was to a maximum depth of 19 meters of seawater for 25 minutes. Six victims (19%) had previous episodes of IPE. There were nine recorded fatalities. Cardiac anomalies dominated the associated or possible contributing factors. These included valvular disease in 29%, transient cardiomyopathies in 26% and dysrhythmias in 16%. Conclusions: Previously reported associations of IPE such as exertion, stress, cold exposure, negative inspiratory pressure, hypertension, overhydration, ascent or surfacing, tight wetsuit, aspiration and certain medications were identified. Cardiac conditions were frequent and included chronic disorders (valvular pathology, coronary artery disease) and transient disorders (dysrhythmias, transient myocardial dysfunction, takotsubo or stress cardiomyopathy). It is likely that the chronic cardiac disorders may have contributed to the IPE, whereas the transient cases could be either sequelae, contributors or coincidental to the IPE.


Assuntos
Mergulho/efeitos adversos , Edema Pulmonar/etiologia , Adulto , Idoso , Autopsia , Doença das Coronárias/patologia , Suscetibilidade a Doenças/etiologia , Suscetibilidade a Doenças/patologia , Evolução Fatal , Feminino , Cardiopatias/complicações , Humanos , Imersão/efeitos adversos , Masculino , Pessoa de Meia-Idade , Oceania/epidemiologia , Esforço Físico , Edema Pulmonar/diagnóstico , Edema Pulmonar/epidemiologia , Edema Pulmonar/patologia , Fatores de Risco , Água do Mar , Distribuição por Sexo , Natação , Cardiomiopatia de Takotsubo/complicações , Adulto Jovem
14.
Zootaxa ; 4623(1): zootaxa.4623.1.8, 2019 Jun 24.
Artigo em Inglês | MEDLINE | ID: mdl-31716278

RESUMO

The detailed morphology and phylogenetic positon of Parafronurus youi Zhou Braasch, 2003 have not been discussed especially so far. In this study, we re-describe and illustrate all stages in more detail. Compared to other genera in the subfamily Ecdyonurinae, the nymph of P. youi is characterized by rounded supracoxal spurs, rounded rectangular head capsule, dense setae on dorsal side of labrum, simple proximal and distal dentisetae, primarily swimming setae of caudal filaments. Upon the latter two characters, this genus seems closer to Asian Rhithrogeniella Ulmer, 1939.


Assuntos
Ephemeroptera , Animais , Ninfa , Filogenia , Natação
15.
Results Probl Cell Differ ; 68: 291-318, 2019.
Artigo em Inglês | MEDLINE | ID: mdl-31598862

RESUMO

Imagine that in 1678 you are Christiaan Huygens or Antonie van Leeuwenhoek seeing paramecia swim gracefully across the field of view of your new microscope. These unicellular, free-living, and swimming cells might have remained a curiosity if not for the ability of H.S. Jennings (Behavior of the lower organisms. Indiana University Press, Bloomington, 1906) and T.M. Sonneborn (Proc Natl Acad Sci USA 23:378-385, 1937) to recognize them for their behavior and genetics, both Mendelian and non-Mendelian. Following many years of painstaking work by Sonneborn and other researchers, Paramecium now serves as a modern model organism that has made specific contributions to cell and molecular biology and development. We will review the continuing usefulness and contributions of Paramecium species in this chapter.Even without a microscope, Paramecium species is visible to the naked eye because of their size (50-300 µ long). Paramecia are holotrichous ciliates, that is, unicellular organisms in the phylum Ciliophora that are covered with cilia. It was the beating of these cilia that propelled them across the slides of the first microscopes and continue to fascinate us today. Over time, Paramecium became a favorite model organism for a large variety of studies. Denis Lyn has called Paramecium the "white rat" of the Ciliophora for their manipulability and amenity to research. We will touch upon the use of Paramecium species to examine swimming behavior, ciliary structure and function, ion channel function, basal body duplication and patterning, non-Mendelian cortical inheritance, programmed DNA rearrangements, regulated secretion and exocytosis, and cell trafficking. In particular, we will focus on the use of P. tetraurelia and P. caudatum.


Assuntos
Movimento Celular , Paramecium/citologia , Paramecium/fisiologia , Cílios/fisiologia , Natação
16.
Wei Sheng Yan Jiu ; 48(4): 611-620, 2019 Jul.
Artigo em Chinês | MEDLINE | ID: mdl-31601344

RESUMO

OBJECTIVE: To investigate the effect of chronic and acute swimming exercise intervention on the mitogen-activated extracellular signal-regulated kinase(MEK) and extracellular signal-regulated kinase 1(ERK1) phosphorylation level in adipose tissues of obesityinduced insulin resistance rats. METHODS: A total of 100 SD rats were randomly divided into control group(n=10) fed with normal diet and high-fat diet group(n=90) fed with high fat diet. After 8 weeks, one third rats(n=30) with upper weight in high-fat diet group were selected and randomly divided into high-fat diet sedentary group(n=10), chronic exercise group(n=10) and acute exercise group(n=10). Under another 8-week high-fat diet feeding, exercise intervention was performed according to the exercise procedure; control group was fed with normal diet for 8 weeks. After exercise intervention, visceral adipose tissues were separated and MEK and ERK1 phosphorylation level in adipose tissue was detected by Western blot method. RESULTS: Chronic exercise intervention significantly reduced body weight, visceral fat weight and visceral fat weight/body weight ratio(P<0. 01), and acute exercise intervention had no significant effect on body weight, visceral fat weight and visceral fat weight/body weight ratio. Both chronic and acute exercise intervention significantly increased body insulin sensitivity(P<0. 05), as well as significantly decreased MEK and ERK1 phosphorylation level in adipose tissues(P<0. 01). CONCLUSION: The improvement of obesity-induced insulin resistance by exercise might be related to inhibited phosphorylation of MEK and ERK1 in adipose tissues.


Assuntos
Tecido Adiposo/metabolismo , Resistência à Insulina/fisiologia , MAP Quinase Quinase 1/metabolismo , Proteína Quinase 3 Ativada por Mitógeno/metabolismo , Condicionamento Físico Animal , Natação , Animais , Dieta Hiperlipídica , Insulina , Fosforilação , Ratos , Ratos Sprague-Dawley
17.
Aquat Toxicol ; 216: 105310, 2019 Nov.
Artigo em Inglês | MEDLINE | ID: mdl-31580997

RESUMO

Pesticide mixtures are increasingly used to fight pest species that developed resistance to pesticides. To assess the pesticide control efficiency and to reduce ecological damage to non-target species, it is important to quantify the effect of these mixtures and compare them with the effect of their single pesticides on pest species, non-target species and their predator-prey interactions. We studied the effects of the chemical pesticide chlorpyrifos (CPF), the biopesticide Bacillus thuringiensis israelensis (Bti) and their mixture both on the direct mortality and on the mortality by predation. We focused on larvae of a CPF-resistant and a non-resistant strain of the vector mosquito Culex quinquefasciatus and its predator, the pygmy backswimmer Plea minutissima. In the CPF-Bti mixture, both pesticides interacted antagonistically for direct mortality. Exposure to the mixture caused equal direct mortality and equal mortality by predation in both strains. As expected, exposure to CPF resulted in less direct mortality and less mortality by predation in the CPF-resistant mosquito strain compared to the non-resistant strain. Notably, Bti caused a higher mortality in the mosquito larvae of the CPF-resistant strain compared to the non-resistant strain. Furthermore, the predator killed more mosquito larvae of the resistant strain compared to the non-resistant strain when exposed before to Bti alone. These observations identify a novel cost of resistance to a chemical pesticide in terms of increased vulnerability to a biopesticide.


Assuntos
Agentes de Controle Biológico/toxicidade , Praguicidas/toxicidade , Comportamento Predatório/efeitos dos fármacos , Animais , Bacillus thuringiensis/efeitos dos fármacos , Clorpirifos/toxicidade , Culex/efeitos dos fármacos , Reação de Congelamento Cataléptica/efeitos dos fármacos , Heterópteros/efeitos dos fármacos , Larva/efeitos dos fármacos , Modelos Lineares , Natação , Poluentes Químicos da Água/toxicidade
18.
Ecotoxicol Environ Saf ; 186: 109760, 2019 Dec 30.
Artigo em Inglês | MEDLINE | ID: mdl-31606642

RESUMO

Graphene nanocomposites are emerging carbon-based materials with interesting electrical, mechanical, optical and magnetic properties, relevant for applications in different fields. Despite this increased use, the impact of graphene nanocomposites residues in the environment has not been properly studied. Thus, the goal of this work was to assess the toxicity of two nickel/graphene nanocomposites (G/Ni1 and G/Ni2) differing in size and shape to Danio rerio embryos. Their toxicity was evaluated using apical (mortality, development and hatching), biochemical [cholinesterase (ChE), glutathione-S-transferase (GST), and catalase (CAT) activities] and behavioral (locomotor activity) endpoints. At the tested concentrations, neither of the nanocomposites presented lethal or developmental effects. Nevertheless, both nanocomposites induced behavioral effects, reducing swimming distances. This effect was, however detected at lower concentrations in the G/Ni1 nanocomposite. At biochemical level, only G/Ni1 nanocomposite showed to interfere with the measured parameters, increasing the activities of ChE, CAT and GST. Differences in the effects induced by the two nanocomposites seem to be related not only with their size, but also with the shape and the ability to continuously release nickel ions to aqueous medium. This work highlights the importance of studying graphene nanocomposites effects to aquatic organisms even when acute toxicity is not expected. The relevance of the effects found in this work need to be further analyzed in light of the consequences to the long-term fitness of the organisms and in light of the environmental concentrations expected for this type of compounds.


Assuntos
Embrião não Mamífero/efeitos dos fármacos , Grafite/toxicidade , Locomoção/efeitos dos fármacos , Nanocompostos/toxicidade , Níquel/toxicidade , Poluentes Químicos da Água/toxicidade , Peixe-Zebra , Animais , Embrião não Mamífero/metabolismo , Fenômenos Magnéticos , Tamanho da Partícula , Natação
19.
Br Dent J ; 227(5): 347-351, 2019 Sep.
Artigo em Inglês | MEDLINE | ID: mdl-31520030

RESUMO

With ongoing changes to the demography of the dental workforce coupled with the changing expectations of those participating in early career post-graduate training, dentistry is experiencing a shift in how it might manage trainees. Drawing on experience from medicine and the anticipated behavioural differences, it is worth considering a way in which training might be able to adapt to the requirements of newer graduates, to ensure that the profession does not lose out on preparing the best candidates possible for careers that improve the state of dentistry both as a vocation and for patient benefit.


Assuntos
Escolha da Profissão , Natação , Odontologia , Emprego , Humanos
20.
PLoS Comput Biol ; 15(9): e1007354, 2019 09.
Artigo em Inglês | MEDLINE | ID: mdl-31518357

RESUMO

A variety of simple models has been proposed to understand the collective motion of animals. These models can be insightful but may lack important elements necessary to predict the motion of each individual in the collective. Adding more detail increases predictability but can make models too complex to be insightful. Here we report that deep attention networks can obtain a model of collective behavior that is simultaneously predictive and insightful thanks to an organization in modules. When using simulated trajectories, the model recovers the ground-truth interaction rule used to generate them, as well as the number of interacting neighbours. For experimental trajectories of large groups of 60-100 zebrafish, Danio rerio, the model obtains that interactions between pairs can approximately be described as repulsive, attractive or as alignment, but only when moving slowly. At high velocities, interactions correspond only to alignment or alignment mixed with repulsion at close distances. The model also shows that each zebrafish decides where to move by aggregating information from the group as a weighted average over neighbours. Weights are higher for neighbours that are close, in a collision path or moving faster in frontal and lateral locations. The network also extracts that the number of interacting individuals is dynamical and typically in the range 8-22, with 1-10 more important ones. Our results suggest that each animal decides by dynamically selecting information from the collective.


Assuntos
Comportamento Animal/fisiologia , Aprendizado Profundo , Comportamento Espacial/fisiologia , Natação/fisiologia , Peixe-Zebra/fisiologia , Animais , Biologia Computacional , Modelos Estatísticos , Comportamento Social
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