Comparação eletromiográfica do músculo vasto medial no exercício de agachamento padrão nos ângulos de 60° e 90° graus

Introdução: O agachamento é um exercício de cadeia cinética fechada, muito utilizado dentro das academias e em planos de reabilitação de pacientes com lesões de joelho, o musculo vasto medial possui bastante importância, pois ele é um grande estabilizador medial patelar. A eletromiografia, esta presente em diversos estudos na área da saúde. Objetivo: O objetivo deste estudo foi verificar se há diferença na ativação do musculo vasto medial no exercício de agachamento padrão nos ângulos de 60° e 90°. Material e Métodos: Foram avaliados 8 indivíduos do sexo masculino , com idade média 23,50 ± 2,83, fisicamente ativos. Os avaliados foram submetidos ao teste de 10RM, fizeram aquecimento e depois tiveram três tentativas para realizar as 10RM, com a carga ajustada pelo responsável da coleta. Eles fizeram o exercício em dois ângulos, o de 60° e o de 90°. Os dados foram expressos nos resultados e nas tabelas em media ± desvio padrão. A estatística descritiva foi utilizada na exposição dos dados. A normalidade dos dados foi verificada pelo teste de ShapiroWilk. A comparação foi realizada através do teste T pareado. Todas as análises foram realizadas no software estatístico SPSS versão 21.0. Adotou-se p < 0,05 como nível de significância. Resultados: A ativação eletromiográfica foi significativamente superior (p = 0,004) no agachamento a 90, quando comparada a 60. Considerações Finais: Conclui–se que a ativação do vasto medial foi maior no ângulo de 90° em relação ao ângulo de 60° no exercício de agachamento padrão.Introduction: The squat is an exercise in closed kinetic chain, widely used in gyms and in patient rehabilitation plans with knee injuries, the vastus muscle has very important because it is a large medial patellar stabilizer. Electromyography, is present in several studies in health. Objective: The objective of this study was to determine whether there is a difference in activation of the vastus muscle in standard squat exercise at angles of 60 ° and 90 °. Material and Methods: A total of 8 males, mean age 23.50 ± 2.83, physically active. The evaluated ones were submitted to the 10RM test, they were heated and then they had three attempts to perfom the 10RM, with the load adjusted by the person responsible for the collection. They did the exercise in two angles, the 60 ° and 90 °. Data were expressed in the results and tables mean ± standard deviation. Descriptive statistics were used for data exposure. The normality of the data was verified by the Shapiro-Wilk test. The comparison was performed using the paired t test. All analyzes were performed using SPSS software version 21.0. It adopted p <0.05 significance level. Results: EMG activation was significantly higher (p = 0.004) in the squat 90 compared to 60. Final Thoughts: We conclude that activation of the vastus was higher at 90 ° angle to the 60 ° angle in standard squat exercise

Small microplastics on beaches of Fernando de Noronha Island, Tropical Atlantic Ocean

Oceanic islands are important areas of environmental, social, economic, and scientific interest. Therefore, it is essential to identify pollutants in these environments, including large (1 mm to ≤ 5 mm) and small microplastics (SMP) (1 μm to ≤ 1 mm). Here, SMP were identified and characterized in the windward (WW) and leeward (LW) beaches of Fernando de Noronha Island. Samples were collected from 900 cm2 quadrants on the strandline of 15 sandy beaches and were sieved through stainless steel sieves with 1 mm mesh. The SMP were characterized according to their shape, colour, and size. Synthetic fibres and fragments were identified, and synthetic fibres were predominant. Statistical differences were not found between the WW and LW beaches (160.0±137.5 particles m-2 and 128.0±84.3 particles m-2, respectively; Mann-Whitney U test: U=198.5; p=0.81) in relation to the total amount of SMP deposited on the beaches. Also, both types/ shapes were present in the two groups of beaches (Friedman’s test, X2 r=6.09; p=0.91). The environmental forcings controlling the transport and potential deposition of synthetic fibres may have been different from those acting on fragments that more resembled the grains of sand in the beaches. Although it is difficult to prevent allochthonous sources of SMP at the small scale, management actions on the island are mandatory to prevent autochthonous sources

Editorial: Microplastics in the marine environment: Sources, distribution, biological effects and socio-economic impacts

inexistenteinfo:eu-repo/semantics/publishedVersio

PLASTICS IN THE ANTARCTIC ENVIRONMENT: ARE WE LOOKING ONLY AT THE TIP OF THE ICEBERG?

The available literature on marine debris and its impacts in the sub-Antarctic Islands, the Antarctic Peninsula and on the coasts of Antarctica was organized and interpreted here. A total of 98 documents covering from 1982 to 2010 were found and 95% had their full contents accessed. Seventy documents were on line scientific abstracts from the Commission on the Conservation of Antarctic Marine Living Resources (CCAMLR). The occurrence of marine debris in the Antarctic environment, fur seals entanglement in marine debris, interactions between seabirds and marine debris and long range transport of benthos on floating plastics were the main issues discussed. Fishing operations in the Southern Ocean were identified as the major source of marine debris, but according to the type of debris reported, plastics from lower latitudes may also cross the Polar Front (PF). Possible links between Antarctic and South America, the closest intercontinental connection, in relation to plastic marine debris pollution are highlighted. As reported for lower latitudinal gradients, plastic pollution is an important problem to the Antarctic environment. However, specific and detailed works are necessary since our current knowledge probably expose only a small part of the real problem. Concerning this sort of pollution in the Antarctic marine and coastal environments, we may be looking solely at the tip of iceberg.PLÁSTICOS   EN   EL   ECOSISTEMA   ANTÁRTICO:   ¿SERÁ   QUE   ESTAMOS   VIENDO SOLAMENTE LA PUNTA DEL ICEBERG?  En este trabajo fue organizada y interpretada la literatura científica relacionada con la presencia y los impactos de basura marina en islas sub-antárticas, en la Península Antártica y en la costa del continente Antártico. Fueron encontrados un total de 98 documentos, publicados entre 1982 e 2010, de los cuales se tuvo acceso a la totalidad del documento en el 95% de los casos. Setenta documentos son resúmenes científicos de la Comisión para la Conservación de los Recursos Marinos en la Antártica (CCAMLR, en inglés) disponibles para consulta en internet. La ocurrencia de basura marina en el ecosistema Antártico  (principalmente  en  playas  arenosas),  el  enredamiento  de  lobos  marinos  en  diferentes ítems de basura, interacciones (ingestión, enredamiento y ocurrencia de basura en áreas de nidificación) entre aves marinas y la basura, y el transporte de organismos bentónicos en plásticos flotantes fueron los asuntos más abordados en los documentos analizados. Operaciones de pesca en el Océano Atlántico Sur fueron identificadas como  la  mayor  fuente  de  basura  para  el  ambiente,  pero  plásticos  originados  en  menores  latitudes  también fueron  identificados,  indicando  transporte  a  través  del  Frente  Polar  (PF,  en  inglés). También  se  abordan  y se  discuten  en  este  trabajo,  posibles  links  entre  la Antártica  y América  del  Sul,  la  conexión  más  próxima intercontinental, en relación a la contaminación por plásticos. Como es reportado para gradientes latitudinales menores, la contaminación por plásticos es un problema relevante para el ecosistema Antártico. Sin embargo, estudios más específicos y detallados son necesarios ya que el conocimiento actual representa, probablemente, solo una pequeña parte del verdadero problema. En relación a este tipo de contaminación en los ambientes marinos y costeros del ecosistema Antártico, posiblemente estamos viendo solo la punta del iceberg. Palabras clave: Especies exóticas; A. gazella; Procellariiformes; hilos de nylon; fragmentos plásticos.PLÁSTICOS NO ECOSSISTEMA ANTÁRTICO: SERÁ QUE ESTAMOS VENDO SOMENTE A PONTA DO ICEBERG? A literatura científica relacionada à presença e aos impactos do lixo marinho em Ilhas Sub-Antárticas, na Península Antártica e na costa do continente Antártico foi organizada e interpretada neste trabalho. Um total de 98 documentos, publicados entre 1982 e 2010, foi encontrado e 95% tiveram seu conteúdo acessado integralmente. Setenta documentos são resumos científicos da Comissão para a Conservação dos Recursos Marinhos na Antártica (CCAMLR, em inglês) disponíveis para consulta na internet.  A ocorrência de lixo marinho no ecossistema Antártico (principalmente praias arenosas), o enredamento de lobos marinhos em itens do lixo, interações (ingestão, enredamento e ocorrência de lixo em áreas de nidificação) entre aves marinhas e o lixo, e o transporte de organismos bentônicos em plásticos flutuantes foram os assuntos mais abordados  nos  documentos  analisados.  Operações  de  pesca  no  Oceano  Atlântico  Sul  foram  identificadas como a maior fonte de lixo para o ambiente, mas plásticos originados em menores latitudes também foram identificados, indicando transporte através da Frente Polar (PF, em inglês). Possíveis links entre a Antárticae a América do Sul, a mais próxima conexão intercontinental, em relação à poluição por plásticos também estão destacados e discutidos neste trabalho. Como reportado para menores gradientes latitudinais, a poluição por plásticos é um problema relevante para o ecossistema Antártico. Entretanto, estudos mais específicos e detalhados são necessários já que o conhecimento atual representa, provavelmente, só uma pequena parte do verdadeiro problema. Em relação a este tipo de poluição nos ambientes marinhos e costeiros do ecossistema Antártico, nós estamos possivelmente vendo somente a ponta do iceberg. Palavras-chave: Espécies exóticas;  A. gazella; Procellariiformes; linhas de nylon; fragmentos plásticos

The geological cycle of plastics and their use as a stratigraphic indicator of the Anthropocene

The rise of plastics since the mid-20th century, both as a material element of modern life and as a growing environmental pollutant, has been widely described. Their distribution in both the terrestrial and marine realms suggests that they are a key geological indicator of the Anthropocene, as a distinctive stratal component. Most immediately evident in terrestrial deposits, they are clearly becoming widespread in marine sedimentary deposits in both shallow- and deep-water settings. They are abundant and widespread as macroscopic fragments and virtually ubiquitous as microplastic particles; these are dispersed by both physical and biological processes, not least via the food chain and the ‘faecal express’ route from surface to sea floor. Plastics are already widely dispersed in sedimentary deposits, and their amount seems likely to grow several-fold over the next few decades. They will continue to be input into the sedimentary cycle over coming millennia as temporary stores – landfill sites – are eroded. Plastics already enable fine time resolution within Anthropocene deposits via the development of their different types and via the artefacts (‘technofossils’) they are moulded into, and many of these may have long-term preservation potential when buried in strata

ANTARCTIC AND SUB-ANTARCTIC SEABIRDS IN SOUTH AMERICA: A REVIEW

We analyzed the reports of Antarctic and Sub-antarctic birds in South American Countries according to scientific papers and gray literature. Forty-eight species were found, and they were observed to occur over oceanic and/or coastal areas of the countries surveyed. Chile was found to present the highest number of seabird species (39), followed by Brazil (38). Species that were less frequently found were Pygoscelis adeliae, Thalassoica antarctica, Pagodroma nivea, Pachyptila salvini and Pterodroma inexpectata, and these were observed only in a single country each. Diomedea exulans, D. epomophora,  Thalassarche melanophris, Macronectes giganteus, Fulmarus glacialoides, Pachyptila desolota and  Oceanites oceanicus were the seabird species most frequently observed, and were found in six out of the seven countries analysed. Of all species found, three are considered endangered species, eight are considered vulnerable, another eight are considered near threatened, according IUCN.AVES MARINAS ANTÁRTICAS Y SUB-ANTÁRTICAS EN AMÉRICA DEL SUR: UNA REVISION.  Analizamos registros de aves marinas antárticas y sub-antárticas en países de América del Sur (Argentina,  Brasil,  Chile,  Ecuador,  Perú,  Uruguay  y  Venezuela)  en  publicaciones  cientíicas,  disertaciones, tesis y libros. Se registraron cuarenta y ocho especies, observadas sobre áreas oceánicas o costeras de los países estudiados. Chile presentó el mayor número de especies migratorias que anidan en la Antártida (39), seguido por Brasil (38). Las especies observadas con mayor frecuencia fueron Diomedea. exulans, D. epomophora, Thalassarche melanophris, Macronectes giganteus, Fulmarus glacialoides, Pachyptila desolota y Oceanites oceanicus; las cuales fueron reportadas en seis de los siete países analizados. Asimismo, las especies con menor frecuencia fueron Pygoscelis adeliae, Thalassoica antarctica, Pagodroma nivea, Pachyptila salvini y Pterodroma inexpectata, observadas apenas en uno sólo de los países analizados. Entre las especies registradas, tres son consideradas especies amenazadas, ocho vulnerables y otras ocho clasificadas como casi amenazadas de  acuerdo  con  IUCN.  Consecuentemente,  es  importante  proteger  no  sólo  las  áreas  de  nidificación  en  el ecosistema Antártico, sino también toda la ruta de migración de estas aves marinas sobre los países de América del Sur. Palabras clave: Aves marinas pelágicas; áreas para conservación; biodiversidad.AVES MARINHAS ANTÁRTICAS E SUB-ANTÁRTICAS NA AMÉRICA DO SUL: UMA REVISÃO. Foram analisados registros de aves marinhas Antárticas e Subantárticas nos países da América do Sul (Argentina, Brasil, Chile, Equador, Peru, Uruguai e Venezuela) com base em artigos e resumos científicos, dissertações, teses e livros. Quarenta e oito espécies foram registradas,  ocorrendo  em  áreas  oceânicas  e/ou costeiras dos países analisados. O Chile apresentou o maior número de espécies de aves migratórias que nidificam na Antártica e em ilhas Sub-Antárticas (39), seguido pelo Brasil (38). Diomedea exulans, D. epomophora, Thalassarche melanophris, Macronectes giganteus, Fulmarus glacialoides, Pachyptila desolota e Oceanites oceanicus foram as aves marinhas mais registradas, encontradas em seis dos sete países amostrados. As espécies menos frequentes foram Pygoscelis adeliae, Thalassoica antarctica, Pagodroma nivea, Pachyptila salvini e Pterodroma inexpectata, observadas em um país cada. Entre as espécies reportadas, três são consideradas ameaçadas  de  extinção,  oito  vulneráveis  e  outras  oito  classificadas  como  quase  ameaçadas  de  extinção,  de acordo com dados da IUCN. Consequentemente, é importante proteger não apenas as áreas de nidificação no ecossistema Antártico, mas toda a rota de migração destas aves marinhas sobre os países da América do Sul. Palavras-chave: Aves marinhas pelágicas; áreas para conservação; biodiversidade

The East Gotland Basin (Baltic Sea) as a candidate Global Boundary Stratotype Section and Point for the Anthropocene series

The short sediment core EMB201/7-4 retrieved from the East Gotland Basin, central Baltic Sea, is explored here as a candidate to host the stratigraphical basis for the Anthropocene series and its equivalent Anthropocene epoch, still to be formalized in the Geological Time Scale. The core has been accurately dated back to 1840 CE using a well-established event stratigraphy approach. A pronounced and significant change occurs at 26.5 cm (dated 1956 ± 4 CE) for a range of geochemical markers including 239+240Pu, 241Am, fly-ash particles, DDT (organochlorine insecticide), total organic carbon, and bulk organic carbon stable isotopes. This stratigraphic level, which corresponds to a change in both lithology and sediment colour related to early anthropogenic-triggered eutrophication of the central Baltic Sea, is proposed as a Global Boundary Stratotype Section and Point for the Anthropocene series

Is the Anthropocene distinct from the Holocene? [abstract only]

The inaugural meeting of the Anthropocene Working Group of the Subcommission on Quaternary Stratigraphy in Berlin (Oct. 2014) produced a consensus statement that “humans have altered geologic processes across the Earth system sufficiently to cause a planetary transition to a new interval of geological time”, with the timing of the onset the focus of continued debate, but with a majority in favour of a mid-20th century beginning. The name has driven the assumption that the Anthropocene should be an epoch, but are its signatures truly driven out of the range evident for most of the Holocene, or are changes comparable or subsidiary to Holocene stages? The evidence rests upon a broad range of signatures reflecting humanity’s significant and increasing modification of Earth systems. These are visible in anthropogenic deposits in the form of the greatest expansion of novel minerals in the last 2.4 billion years and development of ubiquitous materials, such as plastics, present in the environment only in the last 60 years. Globally distributed spherical carbonaceous particles of fly ash represent another near-synchronous and permanent proxy. The artefacts we produce, the technofossils of the future, provide a decadal to annual stratigraphical resolution. These materials and deposits have in recent decades extended into the oceans and increasingly into the subsurface both onshore and offshore. These anthropogenic deposits are transported at rates exceeding those of the sediment carried by rivers by an order of magnitude, fluvial systems themselves showing widespread sediment retention in response to dam construction across most major river systems. The Anthropocene is evident in sediment and glacial ice strata as chemical markers. CO2 in the atmosphere has risen by ~45 percent above pre-Industrial Revolution levels, mainly through combustion of hydrocarbons over a few decades. Although average global temperature increases and resultant sea-level rises are still comparatively small, the shift to more negative δ13C values in tree-rings, limestones, speleothems, calcareous fossils and δ13CO2 in ice forms a permanent record. Nitrogen and phosphorus contents in surface soils has approximately doubled through increased use of fertilizers to increase agricultural yields as the human population has also doubled in the last 50 years. Industrial metals such as Cd, Cr, Cu, Hg, Ni, Pb, Zn and persistent organic compounds have been widely and rapidly dispersed. A clear novel signature is radioactive fallout from atomic weapons testing, initiated in 1945 but becoming global in 1952 and in the case of Pu239 representing a long-lasting marker event. The Earth still has most of its complement of biological species, though many now as small populations: current trends of habitat loss and predation, if maintained, will push the Earth into the sixth mass extinction event in the next few centuries. Dramatic elapsed changes include trans-global species invasions and population modification through agricultural development on land and contamination of coastal zones. Although these changes are not synchronous, within near coastal environments microfauna/flora commonly show pronounced assemblage changes in the mid-20th century. Considering the entire range of environmental changes reflected in stratigraphic signatures, the global, large and rapid scale of change related to the mid-20th century is clearly distinct from previous Holocene signatures, consistent with interpretation of the Anthropocene as a potential epoch

Colonization of the Americas, 'Little Ice Age' climate, and bomb-produced carbon: their role in defining the Anthropocene

A recently published analysis by Lewis and Maslin (Lewis SL and Maslin MA (2015) Defining the Anthropocene. Nature 519: 171–180) has identified two new potential horizons for the Holocene−Anthropocene boundary: 1610 (associated with European colonization of the Americas), or 1964 (the peak of the excess radiocarbon signal arising from atom bomb tests). We discuss both of these novel suggestions, and consider that there is insufficient stratigraphic basis for the former, whereas placing the latter at the peak of the signal rather than at its inception does not follow normal stratigraphical practice. Wherever the boundary is eventually placed, it should be optimized to reflect stratigraphical evidence with the least possible ambiguity

Response to Merritts et al. (2023): The Anthropocene is complex. Defining it is not

Merritts et al. (2023) misrepresent Paul Crutzen's Anthropocene concept as encompassing all significant anthropogenic impacts, extending back many millennia. Crutzen's definition reflects massively enhanced, much more recent human impacts that transformed the Earth System away from the stability of Holocene conditions. His concept of an epoch (hence the ‘cene’ suffix) is more consistent with the strikingly distinct sedimentary record accumulated since the mid-20th century. Waters et al. (2022) highlighted a Great Acceleration Event Array (GAEA) of stratigraphic event markers that are indeed diverse and complex but also tightly clustered around 1950 CE, allowing ultra-high resolution characterization and correlation of a clearly recognisable Anthropocene chronostratigraphic base. The ‘Anthropocene event’ offered by Merritts et al., following Gibbard et al. (2021, 2022), is a highly nuanced concept that obfuscates the transformative human impact of the chronostratigraphic Anthropocene. Waters et al. (2022) restricted the meaning of the term ‘event’ in geology to conform with usual Quaternary practice and improve its utility. They simultaneously recognized an evidence-based Anthropogenic Modification Episode that is more explicitly defined than the highly interpretive interdisciplinary ‘Anthropocene event’ of Gibbard et al. (2021, 2022). The advance of science is best served through clearly developed concepts supported by tightly circumscribed terminology; indeed, improvements to stratigraphy over recent decades have been achieved through increasingly precise definitions, especially for chronostratigraphic units, and not by retaining vague terminology