12 research outputs found
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Strategic planning for wood farming development (Case study: Urmia)
YesWood farming is one of the strategies of agricultural development programs to reform unsustainable exploitation of natural resources. Poplar is one of the known species for wood farming in the country. This species is fast-growing and has numerous Colognes has the ability to adapt to different climatic conditions. Fast growth, good economic returns and traditional agricultural knowledge, favorable habitat to agriculture are advantages of poplar for agricultural development. However, the result of previous studies indicates existing barriers to the development of plantation and its development need strategic planning. What seem essential today are strategies to overcome these obstacles. Accordingly, this present study with a holistic view trying to identify the strengths, weaknesses, opportunities and threats of poplar farming. And the most appropriate strategies for the development of poplar farming in Urmia have offered. This research was a Field study and conducted using questionnaires. In this study, strategies were defined using SWOT analysis and the strategies were prioritized using analysis network process. The results showed the history of poplar farming in this region is the most important benefit to development and the many uses for poplar wood is the next priority. Increasingly replacement of poplar farming with alternative cultures is one of the main weaknesses of poplar farming development in this region. After that long return of profitability in poplar farming is the second priority. The most important opportunities for the development were the development of credit specialists to support of poplar farming and the most important threat was lack of annual financing of farmers. Also the results of strategic prioritization showed, Modern irrigation methods to reduce water consumption and planning to teach correct principles of technical planting, farming and harvesting are considered as the most important strategies
Evaluating the Viscoelastic Properties of Tissue from Laser Speckle Fluctuations
Most pathological conditions such as atherosclerosis, cancer, neurodegenerative, and orthopedic disorders are accompanied with alterations in tissue viscoelasticity. Laser Speckle Rheology (LSR) is a novel optical technology that provides the invaluable potential for mechanical assessment of tissue in situ. In LSR, the specimen is illuminated with coherent light and the time constant of speckle fluctuations, τ, is measured using a high speed camera. Prior work indicates that τ is closely correlated with tissue microstructure and composition. Here, we investigate the relationship between LSR measurements of τ and sample mechanical properties defined by the viscoelastic modulus, G*. Phantoms and tissue samples over a broad range of viscoelastic properties are evaluated using LSR and conventional mechanical testing. Results demonstrate a strong correlation between τ and |G*| for both phantom (r = 0.79, p <0.0001) and tissue (r = 0.88, p<0.0001) specimens, establishing the unique capability of LSR in characterizing tissue viscoelasticity
Speckle-scale focusing in the diffusive regime with time reversal of variance-encoded light (TROVE)
Focusing of light in the diffusive regime inside scattering media has long been considered impossible. Recently, this limitation has been overcome with time reversal of ultrasound-encoded light (TRUE), but the resolution of this approach is fundamentally limited by the large number of optical modes within the ultrasound focus. Here, we introduce a new approach, time reversal of variance-encoded light (TROVE), which demixes these spatial modes by variance encoding to break the resolution barrier imposed by the ultrasound. By encoding individual spatial modes inside the scattering sample with unique variances, we effectively uncouple the system resolution from the size of the ultrasound focus. This enables us to demonstrate optical focusing and imaging with diffuse light at an unprecedented, speckle-scale lateral resolution of ~5 µm
Clinical evaluation of whole blood prothrombin time (PT) and international normalized ratio (INR) using a Laser Speckle Rheology sensor
The emergence of optical elastography in biomedicine
Optical elastography, the use of optics to characterize and map the mechanical properties of biological tissue, involves measuring the deformation of tissue in response to a load. Such measurements may be used to form an image of a mechanical property, often elastic modulus, with the resulting mechanical contrast complementary to the more familiar optical contrast. Optical elastography is experiencing new impetus in response to developments in the closely related fields of cell mechanics and medical imaging, aided by advances in photonics technology, and through probing the microscale between that of cells and whole tissues. Two techniques — optical coherence elastography and Brillouin microscopy — have recently shown particular promise for medical applications, such as in ophthalmology and oncology, and as new techniques in cell mechanics
Real-time intraoperative monitoring of blood coagulability via coherence-gated light scattering
When characterizing dynamic processes, ergodicity - that is, the equivalence of time averages and of averages over a system\u27s possible microstates - is often invoked. Yet many complex social, economic and material systems are such that practical observations cannot survey the entire ensemble of microstates. In the case of non-ergodic fluids, their slow structural dynamics makes such an approach prohibitive. Blood is a prominent example of a non-ergodic, complex fluid for which today\u27s standards for coagulation tests in vivo are chemically induced offline assays. Here, we show that heterodyne amplification - that is, amplification of a signal by frequency conversion - combined with suitable control of spatiotemporal coherence permits measurements of non-stationary dynamics in non-ergodic, complex media. By taking advantage of this approach, we developed an optical-fibre-based tool that can be directly incorporated into standard vascular-access devices for real-time monitoring of blood coagulability in the operating room