The Pioneer Anomaly

Radio-metric Doppler tracking data received from the Pioneer 10 and 11 spacecraft from heliocentric distances of 20-70 AU has consistently indicated the presence of a small, anomalous, blue-shifted frequency drift uniformly changing with a rate of ~6 x 10^{-9} Hz/s. Ultimately, the drift was interpreted as a constant sunward deceleration of each particular spacecraft at the level of a_P = (8.74 +/- 1.33) x 10^{-10} m/s^2. This apparent violation of the Newton's gravitational inverse-square law has become known as the Pioneer anomaly; the nature of this anomaly remains unexplained. In this review, we summarize the current knowledge of the physical properties of the anomaly and the conditions that led to its detection and characterization. We review various mechanisms proposed to explain the anomaly and discuss the current state of efforts to determine its nature. A comprehensive new investigation of the anomalous behavior of the two Pioneers has begun recently. The new efforts rely on the much-extended set of radio-metric Doppler data for both spacecraft in conjunction with the newly available complete record of their telemetry files and a large archive of original project documentation. As the new study is yet to report its findings, this review provides the necessary background for the new results to appear in the near future. In particular, we provide a significant amount of information on the design, operations and behavior of the two Pioneers during their entire missions, including descriptions of various data formats and techniques used for their navigation and radio-science data analysis. As most of this information was recovered relatively recently, it was not used in the previous studies of the Pioneer anomaly, but it is critical for the new investigation.Comment: 165 pages, 40 figures, 16 tables; accepted for publication in Living Reviews in Relativit

Early Devonian (Late Emsian) shark fin remains (Chondrichthyes) from the Paraná Basin, southern Brazil

This is an open-access article distributed under the terms of the Creative Commons Attribution License [Attribution-NonCommercial 4.0 International (CC BY-NC 4.0)]. The attached file is the published version of the article

Análise biomecânica dos efeitos da crioterapia no tratamento da lesão muscular aguda Biomechanical analysis of the cryotherapy effects in the treatment of acute muscular injury

A crioterapia é amplamente utilizada por atletas profissionais e amadores no tratamento agudo de lesões musculares. Este trabalho teve como objetivo analisar as propriedades mecânicas do músculo gastrocnêmio lesionado por impacto direto e tratado com crioterapia. Para tanto, foram utilizadas 24 ratas Wistar, divididas em três grupos experimentais: grupo controle (C): animais mantidos em gaiolas-padrão por seis dias; grupo lesionado (L): animais submetidos à lesão por mecanismo de impacto no gastrocnêmio, sem tratamento e mantidos em gaiolas-padrão por seis dias; grupo lesionado e tratado com crioterapia (LC): animais submetidos à lesão, tratados com uma sessão de crioterapia, imediatamente após a lesão e mantidos em gaiolas-padrão por seis dias. Após essas etapas, os animais foram submetidos à eutanásia para que fossem realizados os ensaios mecânicos de tração dos músculos gastrocnêmios direitos, na máquina universal de ensaios (EMIC®). A partir dos gráficos carga versus alongamento de cada ensaio, foram calculadas as seguintes propriedades mecânicas: carga no limite máximo (CLM), alongamento no limite máximo (ALM) e rigidez (R). No ALM, o grupo C apresentou diferença estatística (p < 0,05) somente quando comparado com o L. Quando analisadas carga máxima e rigidez, houve diferença estatística (p < 0,05) nos três grupos. Assim, enquanto os músculos lesionados sem tratamento apresentaram diminuição de todas as propriedades mecânicas analisadas, os tratados com crioterapia mostraram melhora das propriedades, porém, sem alcançar o grupo controle. Dessa forma, podemos concluir que a sessão de crioterapia por imersão imediata após a lesão promoveu melhora das propriedades mecânicas analisadas.<br>Cryotherapy is widespread used in the acute treatment of muscle injuries of professional and unprofessional athletes. The purpose of this study was the investigation of mechanical properties of gastrocnemius muscle submitted to a impact mechanism of injury and treated with cryoterapy. Therefore, twenty four female Wistar rats were divided into three groups: Control (C): animals housed in standard cages for six days; Lesion (L): animals submitted to a direct impact mechanism of injury in the gastrocnemius muscle, without any treatment and kept into standard cages during six days; Lesion e cryotherapy (LC): animals submitted to the contusion, treated with a single session of cryotherapy immediately after lesion and housed in standard cages during six days. After those protocols, the rats were killed and their right gastrocnemius muscle were dissected and submitted to a mechanical test of traction in a universal assays machine (EMIC®). From the load versus elongation curves, the following mechanical properties were obtained: Maximum limit load (MLL), maximum limit elongation (MLE) and stiffness (St). There was a statistically difference between all groups in MLL and St. However, in the MLE there was statistically difference only between groups C and L (p<0,05). The results showed that the muscle contusion without treatment led to exasperation of all analyzed mechanical properties. Conversely, cryotherapy improved the muscle properties, although they had not reached the control group values. It can be concluded that the cryotherapy applied immediately after muscle contusion improved the muscle mechanical properties

Anthropogenic impact on a pregnant Cuvier’s beaked whale (Ziphius cavirostris) stranded in Brazil

Background: Because of their usually cryptic behaviour, most knowledge on the biology of beaked whales are from records of stranded animals. Although the Cuvier’s beaked whale (Ziphius cavirostris) is the best known species of the ziphiidae family, little information on its reproduction is available. Results: Here we report on the stranding of a dead pregnant female with clear signs of anthropogenic impact, including the presence of a fishing artefact in the stomach. Conclusions: The region of the stranding (north-eastern coast of Brazil) is an area of increasing interest for oil and gas exploitation. Conservation concerns may arise from findings such as the one presented and discussed here