43 research outputs found
Low-cost GPS/GNSS Real Time Kinematic receiver to build a cartographic grid on the ground for an archaeological survey at Piscina Torta (Italy)
The collection of samples and finds for archaeological surveys is traditionally based on the establishment of grids that allow the area under study to be discretized into generally square cells in order to allow a statistical assessment of the highest or lowest concentration of finds. Currently, such grids are implemented in a local coordinate system established by means of total stations or tape measures. We validated the capabilities of a low-cost GPS/GNSS Real Time Kinematic (RTK) receiver to build a grid during the intensive archaeological survey of the Piscina Torta site (Italy), in the framework of the Salt and Power project of the University of Groningen. We also tested not using a local grid but a cartographic grid (WGS84 UTM zone 33 N) and naming the single cells with the coordinates of one of its vertices. This approach is greatly facilitated by the recent availability of inexpensive RTK receivers with few centimetres accuracy, very small in size and weight and with hardware protected enough to be used in the field. This would facilitate the use and exchange of the data (e.g. about the materials collected in the cell) among the scientific community and can be thought of as a proposal for standardization
Low-cost GPS/GNSS Real Time Kinematic receiver to build a cartographic grid on the ground for an archaeological survey at Piscina Torta (Italy)
The collection of samples and finds for archaeological surveys is traditionally based on the establishment of grids that allow the area under study to be discretized into generally square cells in order to allow a statistical assessment of the highest or lowest concentration of finds. Currently, such grids are implemented in a local coordinate system established by means of total stations or tape measures. We validated the capabilities of a low-cost GPS/GNSS Real Time Kinematic (RTK) receiver to build a grid during the intensive archaeological survey of the Piscina Torta site (Italy), in the framework of the Salt and Power project of the University of Groningen. We also tested not using a local grid but a cartographic grid (WGS84 UTM zone 33 N) and naming the single cells with the coordinates of one of its vertices. This approach is greatly facilitated by the recent availability of inexpensive RTK receivers with few centimetres accuracy, very small in size and weight and with hardware protected enough to be used in the field. This would facilitate the use and exchange of the data (e.g. about the materials collected in the cell) among the scientific community and can be thought of as a proposal for standardization
Burden of Disease Caused by Otitis Media: Systematic Review and Global Estimates
<div><h3>Background</h3><p>Otitis media (OM) is a leading cause of health care visits and drugs prescription. Its complications and sequelae are important causes of preventable hearing loss, particularly in developing countries. Within the Global Burden of Diseases, Injuries, and Risk Factors Study, for the year 2005 we estimated the incidence of acute OM, chronic suppurative OM, and related hearing loss and mortality for all ages and the 21 WHO regional areas.</p> <h3>Methods</h3><p>We identified risk factors, complications and sequelae of OM. We carried out an extensive literature review (Medline, Embase, Lilacs and Wholis) which lead to the selection of 114 papers comprising relevant data. Data were available from 15 of the 21 WHO regions. To estimate incidence and prevalence for all countries we adopted a two stage approach based on risk factors formulas and regression modelling.</p> <h3>Results</h3><p>Acute OM incidence rate is 10.85% i.e. 709million cases each year with 51% of these occurring in under-fives. Chronic suppurative OM incidence rate is 4.76â° i.e. 31million cases, with 22.6% of cases occurring annually in under-fives. OM-related hearing impairment has a prevalence of 30.82 per ten-thousand. Each year 21thousand people die due to complications of OM.</p> <h3>Conclusions</h3><p>Our study is the first attempt to systematically review the available information and provide global estimates for OM and related conditions. The overall burden deriving from AOM, CSOM and their sequelae is considerable, particularly in the first five years of life and in the poorest countries. The findings call for incorporating OM-focused action within preventive and case management strategies, with emphasis on the more affected.</p> </div
Numerical approximations for fractional elliptic equations
We provide a novel approach to the numerical solution of the family of nonlocal elliptic equations (âÎ)su = f in Ω, subject to some homogeneous boundary conditions on âΩ, where s â (0,1), Ω â ân is a bounded domain, and (-Î)s is the spectral fractional Laplacian associated to on âΩ. We use the solution representation (âÎ)âs f together with its singular integral expression given by the method of semigroups. By combining finite element discretizations for the heat semigroup with monotone quadratures for the singular integral we obtain accurate numerical solutions. Roughly speaking, given a datum f in a suitable fractional Sobolev space of order r â„ 0 and the discretization parameter h > 0, our numerical scheme converges as O(hr+2s), providing super quadratic convergence rates up to O(h4) for sufficiently regular data, or simply O(h2s) for merely f â L2 (Ω). We also extend the proposed framework to the case of nonhomogeneous boundary conditions and support our results with some illustrative numerical tests
Selective killing of spinal cord neural stem cells impairs locomotor recovery in a mouse model of spinal cord injury
Abstract Background Spinal cord injury (SCI) is a devastating condition mainly deriving from a traumatic damage of the spinal cord (SC). Immune cells and endogenous SC-neural stem cells (SC-NSCs) play a critical role in wound healing processes, although both are ineffective to completely restore tissue functioning. The role of SC-NSCs in SCI and, in particular, whether such cells can interplay with the immune response are poorly investigated issues, although mechanisms governing such interactions might open new avenues to develop novel therapeutic approaches. Methods We used two transgenic mouse lines to trace as well as to kill SC-NSCs in mice receiving SCI. We used Nestin CreERT2 mice to trace SC-NSCs descendants in the spinal cord of mice subjected to SCI. While mice carrying the suicide gene thymidine kinase (TK) along with the GFP reporter, under the control of the Nestin promoter regions (NestinTK mice) were used to label and selectively kill SC-NSCs. Results We found that SC-NSCs are capable to self-activate after SCI. In addition, a significant worsening of clinical and pathological features of SCI was observed in the NestinTK mice, upon selective ablation of SC-NSCs before the injury induction. Finally, mice lacking in SC-NSCs and receiving SCI displayed reduced levels of different neurotrophic factors in the SC and significantly higher number of M1-like myeloid cells. Conclusion Our data show that SC-NSCs undergo cell proliferation in response to traumatic spinal cord injury. Mice lacking SC-NSCs display overt microglia activation and exaggerate expression of pro-inflammatory cytokines. The absence of SC-NSCs impaired functional recovery as well as neuronal and oligodendrocyte cell survival. Collectively our data indicate that SC-NSCs can interact with microglia/macrophages modulating their activation/responses and that such interaction is importantly involved in mechanisms leading tissue recovery