Photoacoustic section imaging with integrating detectors

Photoacoustic  section  imaging  is  a  method  for visualizing  structures  with  optical contrast  in selected  layers  of  an  extended  object.  In  order  to avoid  resolution limitations  that  are  due  to commonly used ultrasound detectors of finite size, we propose  the  use  of  extended,  integrating cylindrical  elements  for  focusing  the acoustic detection  into  the  selected  section.  Two  imaging methods  based  on piezoelectric  and  optical detection  are  presented.  Resolution  limits  and results on zebra fish are demonstrated

Foreseeing Neutrino spectra in Deep Core

Atmospheric muon neutrino in Deep Core (whose rate and spectra might be soon available) should exhibit a suppression (due to tens GeV up-going muon neutrino converted into tau flavor) that must be imprinted in out-coming rate spectra. We estimate here our independent muon neutrino spectra based on SK and its projected record on Deep Core Channels. Our estimate (based on cosmic rays, muon records and tested Super-Kamiokande (SK) data) differs both in shape and in rate from other previous published spectra. The expected rate might exhibit a minimum near channel 6 of Deep Core strings and it should manifest strong signature for flavor mixing (mostly between channel 4--15)and a relevant anomaly for eventual CPT violation (MINOS like) written at channel 3--6,whose statistical weight (mainly at channel 5) might soon confirm or dismiss MINOS CPT claim. At the flux minimum around channel 6, (a flux suppressed respect the non oscillated case at least by an order of magnitude) the atmospheric neutrino paucity offers a better windows to a twenty GeV Neutrino Astronomy. Therefore by doubling the string array we may foresee a richer rate and a more complete (zenith and azimuth) atmospheric neutrino distribution and an exciting first twenty GeV Astronomy.Comment: 8 pages, 8 figure

Label-free imaging of zebrafish larvae in vivo by photoacoustic microscopy

Zebrafish play an important role in biological and biomedical research. Traditional in vivo imaging methods for studying zebrafish larvae primarily require fluorescence labeling. In this work, relying on tissue intrinsic optical absorption contrast, we acquired high resolution label-free 3D images of zebrafish larvae by using photoacoustic microscopy (PAM) in vivo. The spatial resolution reaches several microns, allowing the study of microstructures in various living organs. We demonstrated that our method has the potential to be a powerful non-invasive imaging method for studying various small animal models, including zebrafish larvae, Caenorhabditis elegans, frogs and drosophila larvae

ANÁLISE COMPARATIVA DE PARÂMETROS DO SOLO OBTIDOS POR MEIO DE SONDAGEM DO TIPO SPT E CPTU

Surgem dúvidas no momento de implantar uma nova obra de construção civil qual tipo de investigação geotécnica melhor se adequa ao tipo de solo e ao porte da edificação a ser construída. Diante desse questionamento decidiu-se realizar um estudo comparativo, buscando verificar as diferenças dos resultados entre dois métodos para determinar a capacidade de carga em fundações profundas muito utilizados pela comunidade de engenheiros especializados em fundações, o SPT e o CPTu. Realizou-se estimativa de parâmetros do solo por meio de correlações sugeridas por autores diversos. Com a resultante destas estimativas pode-se concluir que a diferença entre os parâmetros baseando-se em um ou outro tipo de sondagem se demonstrou muito semelhante, sem grandes disparidades. Neste trabalho fez-se também a estimativa de capacidade de carga baseando-se em vários métodos teóricos e semi-empíricos. Na maioria dos resultados por métodos teóricos obtiveram-se resultados superiores de resistência comparando-se aos semi-empíricos. Dentre os métodos semi-empíricos, quando utilizados dados do CPTu as estimativas de carga foram menores que os resultados baseados no ensaio de SPT. Ao final de todos estes estudos conclui-se que por meio do ensaio de CPTu os resultados obtidos são mais conservadores na maioria das situações e se levarmos em consideração o método de execução do ensaio pode-se tratar o método como mais seguro em seus resultados, pois demanda maior controle tecnológico e apresenta resultados ao longo de todo o perfil, não apenas a cada metro de perfuração, como ocorre com o SPT

Thermography and thermoregulation of the face

BACKGROUND: Although clinical diagnosis of thermoregulation is gaining in importance there is no consistent evidence on the value of thermography of the facial region. In particular there are no reference values established with standardised methods. METHODS: Skin temperatures were measured in the facial area at 32 fixed measuring sites in 26 health subjects (7–72 years) with the aid of a contact thermograph (Eidatherm). A total of 6 measurements were performed separately for the two sides of the face at intervals of equal lengths (4 hours) over a period of 24 hours. Thermoregulation was triggered by application of a cold stimulus in the region of the ipsilateral ear lobe. RESULTS: Comparison of the sides revealed significant asymmetry of face temperature. The left side of the face showed a temperature that was on the average 0.1°C lower than on the right. No increase in temperature was found following application of the cold stimulus. However, a significant circadian rhythm with mean temperature differences of 0.7°C was observed. CONCLUSION: The results obtained should be seen as an initial basis for compiling an exact thermoprofile of the surface temperature of the facial region that takes into account the circadian rhythm, thus closing gaps in studies on physiological changes in the temperature of the skin of the face

Application of infrared thermography in computer aided diagnosis

The invention of thermography, in the 1950s, posed a formidable problem to the research community: What is the relationship between disease and heat radiation captured with Infrared (IR) cameras? The research community responded with a continuous effort to find this crucial relationship. This effort was aided by advances in processing techniques, improved sensitivity and spatial resolution of thermal sensors. However, despite this progress fundamental issues with this imaging modality still remain. The main problem is that the link between disease and heat radiation is complex and in many cases even non-linear. Furthermore, the change in heat radiation as well as the change in radiation pattern, which indicate disease, is minute. On a technical level, this poses high requirements on image capturing and processing. On a more abstract level, these problems lead to inter-observer variability and on an even more abstract level they lead to a lack of trust in this imaging modality. In this review, we adopt the position that these problems can only be solved through a strict application of scientific principles and objective performance assessment. Computing machinery is inherently objective; this helps us to apply scientific principles in a transparent way and to assess the performance results. As a consequence, we aim to promote thermography based Computer-Aided Diagnosis (CAD) systems. Another benefit of CAD systems comes from the fact that the diagnostic accuracy is linked to the capability of the computing machinery and, in general, computers become ever more potent. We predict that a pervasive application of computers and networking technology in medicine will help us to overcome the shortcomings of any single imaging modality and this will pave the way for integrated health care systems which maximize the quality of patient care