Actualización en radiología dental: Radiología convencional Vs digital

Desde su incorporación a la práctica odontológica la radiología digital ha experimentado un importante desarrollo. El continuo avance de las tecnologías en las que se sustenta ha dotado a estos sistemas de interesantes prestaciones que pueden facilitar el diagnóstico y manejo de imágenes radiográficas. Con estos avances la radiología digital ha despertado un interés creciente entre los profesionales de la odontología, especialmente durante los últimos años, en los que ha aumentado notoriamente tanto la cantidad de sistemas comercializados como el número de odontólogos que han decidido sustituir la radiología convencional por un sistema digital en sus clínicas. En esta revisión de la literatura se tratará de ofrecer una visión actualizada de los distintos sistemas disponibles en la actualidad, así como una comparativa entre ellos basada en estudios publicados recientemente. Since its appearance in dentistry, digital radiology has experienced a notorious development. A constant advance in the corresponding technologies has enhanced these digital systems with interesting features which may facilitate radiological diagnosis and image management. Due to these advances digital radiology has elicited a growing interest in dentistry. Specially during the last years there has been an increase both in the amount of available systems and in the number of dentists who have incorporated a digital system in their offices. This literature review aims to offer an updated view of the available systems and a comparison of them based in recent studies

Multi-currency credit default swaps

Credit default swaps (CDS) on a reference entity may be traded in multiple currencies, in that, protection upon default may be offered either in the currency where the entity resides, or in a more liquid and global foreign currency. In this situation, currency fluctuations clearly introduce a source of risk on CDS spreads. For emerging markets, but in some cases even in well-developed markets, the risk of dramatic foreign exchange (FX)-rate devaluation in conjunction with default events is relevant. We address this issue by proposing and implementing a model that considers the risk of foreign currency devaluation that is synchronous with default of the reference entity. As a fundamental case, we consider the sovereign CDSs on Italy, quoted both in EUR and USD. Preliminary results indicate that perceived risks of devaluation can induce a significant basis across domestic and foreign CDS quotes. For the Republic of Italy, a USD CDS spread quote of 440 bps can translate into an EUR quote of 350bps in the middle of the Euro-debt crisis in the first week of May 2012. More recently, from June 2013, the basis spreads between the EUR quotes and the USD quotes are in the range around 40bps. We explain in detail the sources for such discrepancies. Our modeling approach is based on the reduced form framework for credit risk, where the default time is modeled in a Cox process setting with explicit diffusion dynamics for default intensity/hazard rate and exponential jump to default. For the FX part, we include an explicit default-driven jump in the FX dynamics. As our results show, such a mechanism provides a further and more effective way to model credit/FX dependency than the instantaneous correlation that can be imposed among the driving Brownian motions of default intensity and FX rates, as it is not possible to explain the observed basis spreads during the Euro-debt crisis by using the latter mechanism alone

Materials study to implement a 3D printer system to repair road pavement potholes

InfraRob is a research project funded by the European Commission's research programme Horizon 2020 that aims to maintain integrity, performance, and safety of the road infrastructure through autonomous robotized solutions and modularization. A specific task of the project is focused on the development of a system 3D printer able to extrude a specific mixture for filling in small cracks and potholes, to be integrated with an existing small autonomous carrier. The first step of the research deals with the definition of the optimal parameters of the system 3D printer/mixture, by studying in parallel the material design and the printer design. This paper presents the study performed on a mixture chosen among those commonly used for road potholes repair. The mixture is studied to achieve and balance the different conflicting performances: consistence, flowability homogeneity, and internal structure. In addition to the basic components, the use of special additives has also been explored to improve the plasticity and adhesivity of the mixture. The first phase of tests is conducted to define the main printing controls: i) Extrudability control: materials for 3D printing need to have an acceptable degree of extrudability, which is related to the capacity of a material to pass continuously through the printing head; ii) Flowability control, to ensure the mixture can be easy-pumpable in the delivery system and easy-usable on the crack or the pothole to be filed-in; iii) Setting time control: printing material requires a certain setting time to maintain a consistent flow rate for good extrudability, thus appropriate additives are needed to control the setting time. The second phase includes in situ tests to verify the compaction of the mixture under the traffic loads. The paper presents the results of the lab and in situ tests, and the features of the chosen mix, suitable to be managed by the 3D printer

Cover crop for a sustainable viticulture: Effects on soil properties and table grape production

Cover crops are increasingly adopted in viticulture to enhance soil quality and balance the vegetative and reproductive growth of vines. Nevertheless, this sustainable practice has been only recently used for table grape viticulture, with results often contrasting. The aim of this study was to assess the effect of a fescue (Festuca arundinacea Schreb.) cover crop on soil quality, yield, and grape qualitative parameters in a table grape vineyard (cv "Italia") located in southern Italy, comparing results with the conventional tillage. Soil organic carbon (C), total nitrogen (N), microbial biomass C (MBC), β-glucosidase (BGLU) and alkaline phosphomonoesterase (APME) activities were assessed during three growing seasons (2012-2014) and three phenological stages. The trend of soil chemical and microbiological properties was jointly influenced by the soil management system, growing season and phenological stage. Compared to conventional tillage, cover crops increased, on average, soil organic C, total N, MBC, BGLU and APME by 136%, 93%, 112%, 100% and 62%, respectively. Slight or no effects of cover crops were observed on grape quality and yield, except for 2012 (the driest season), when a yield reduction occurred. This study reveals that cover crops strongly enhance soil quality in the short-term, with potential advantages for grape production in the long-term

Family memories in the home: contrasting physical and digital mementos

We carried out fieldwork to characterise and compare physical and digital mementos in the home. Physical mementos are highly valued, heterogeneous and support different types of recollection. Contrary to expectations, we found physical mementos are not purely representational, and can involve appropriating common objects and more idiosyncratic forms. In contrast, digital mementos were initially perceived as less valuable, although participants later reconsidered this. Digital mementos were somewhat limited in function and expression, largely involving representational photos and videos, and infrequently accessed. We explain these digital limitations and conclude with design guidelines for digital mementos, including better techniques for accessing and integrating these into everyday life, allowing them to acquire the symbolic associations and lasting value that characterise their physical counterparts

Synaptic Integration of Adult-Born Hippocampal Neurons Is Locally Controlled by Astrocytes.

Adult neurogenesis is regulated by the neurogenic niche, through mechanisms that remain poorly defined. Here, we investigated whether niche-constituting astrocytes influence the maturation of adult-born hippocampal neurons using two independent transgenic approaches to block vesicular release from astrocytes. In these models, adult-born neurons but not mature neurons showed reduced glutamatergic synaptic input and dendritic spine density that was accompanied with lower functional integration and cell survival. By taking advantage of the mosaic expression of transgenes in astrocytes, we found that spine density was reduced exclusively in segments intersecting blocked astrocytes, revealing an extrinsic, local control of spine formation. Defects in NMDA receptor (NMDAR)-mediated synaptic transmission and dendrite maturation were partially restored by exogenous D-serine, whose extracellular level was decreased in transgenic models. Together, these results reveal a critical role for adult astrocytes in local dendritic spine maturation, which is necessary for the NMDAR-dependent functional integration of newborn neurons

The relationship between smoking exposure and p53 overexpression in colorectal cancer.

Although epidemiological studies of the relationship between cigarette smoking and colorectal cancer risk have been equivocal, a positive association is consistently found for colorectal adenoma development. We performed an epidemiological study to determine whether p53 protein overexpression, in tumours obtained at the time of resection, is associated with cigarette exposure in colorectal cancer. A total of 163 colorectal cancer cases and 326 healthy controls responded to a standardised questionnaire on colorectal cancer risk factors including detailed information on their history of cigarette smoking. All patients' tumours were analysed immunohistochemically for p53 overexpression using an avidin-biotin immunoperoxidase procedure and polyclonal anti-p53 antibody CM1. Comparison of colorectal cases with controls revealed an elevated risk for ex-smokers (OR = 1.34, 95% CI 0.85-2.12) and current smokers (OR = 1.13, 95% CI 0.63-2.02) when compared with non-smokers. No dose-response relationship was found for total pack-years of smoking (trend test: P = 0.19). However, a trend for total pack-years of smoking was found when p53-positive cases were compared with p53-negative cases suggesting aetiological, heterogeneity (trend test: P = 0.06). Estimating the individual relative risk of developing a p53-positive tumour relative to controls showed no associations for smoking status or total pack-years of smoking. However, when p53-negative cases were compared with controls, an elevated risk was found for ex-smokers (OR = 1.84, 95% CI 1.00-3.37) and current years of smoking (trend test: P = 0.03). Colorectal tumours developing through p53-positive dependent pathways were not associated with smoking exposure. A significant increase in risk was observed for the p53-negative independent pathway with smoking. p53 overexpression appears to be associated with smoking exposure in colorectal cancer