Telaprevir for Retreatment of HCV Infection ZEUZEM, Stefan; ANDREONE, Pietro; FERENCI, Peter ...
The New England journal of medicine,
06/2011, Letnik:
364, Številka:
25
Journal Article
•An error propagation analysis of GNSS over the laser scan measurements.•A scan matching approach fused with GNSS measurements.•Analysis of the crown surface area, crown volume, and crown porosity.
...Currently, 3D point clouds are obtained via LiDAR (Light Detection and Ranging) sensors to compute vegetation parameters to enhance agricultural operations. However, such a point cloud is intrinsically dependent on the GNSS (global navigation satellite system) antenna used to have absolute positioning of the sensor within the grove. Therefore, the error associated with the GNSS receiver is propagated to the LiDAR readings and, thus, to the crown or orchard parameters. In this work, we first describe the error propagation of GNSS over the laser scan measurements. Second, we present our proposal to overcome this effect based only on the LiDAR readings. Such a proposal uses a scan matching approach to reduce the error associated with the GNSS receiver. To accomplish such purpose, we fuse the information from the scan matching estimations with the GNSS measurements. In the experiments, we statistically analyze the dependence of the grove parameters extracted from the 3D point cloud -specifically crown surface area, crown volume, and crown porosity- to the localization error. We carried out 150 trials with positioning errors ranging from 0.01 meters (ground truth) to 2 meters. When using only GNSS as a localization system, the results showed that errors associated with the estimation of vegetation parameters increased more than 100 % when positioning error was equal or bigger than 1 meter. On the other hand, when our proposal was used as a localization system, the results showed that for the same case of 1 meter, the estimation of orchard parameters improved in 20 % overall. However, in lower positioning errors of the GNSS, the estimation of orchard parameters were improved up to 50% overall. These results suggest that our work could lead to better decisions in agricultural operations, which are based on foliar parameter measurements, without the use of external hardware.
This work tackles the commissioning and validation of a novel combination of a synchrotron-based proton beam therapy system (Hitachi, Ltd.) for use with a Monte Carlo treatment planning system (TPS). ...Four crucial aspects in this configuration have been investigated: (1) Monte Carlo-based correction performed by the TPS to the measured integrated depth-dose curves (IDD), (2) circular spot modelling with a single Gaussian function to characterize the synchrotron physical spot, which is elliptical, (3) the modelling of the range shifter that enables using only one set of measurements in open beams, and (4) the Monte Carlo dose calculation model in small fields.
Integrated depth-dose curves were measured with a PTW Bragg peak chamber and corrected, with a Monte Carlo model, to account for energy absorbed outside the detector. The elliptical spot was measured by IBA Lynx scintillator, EBT3 films and PTW microDiamond. The accuracy of the TPS (RayStation, RaySearch Laboratories) at spot modelling with a circular Gaussian function was assessed.
The beam model was validated using spread-out Bragg peak (SOBP) fields. We took single-point doses at several depths through the central axis using a PTW Farmer chamber, for fields between 2 × 2cm and 30 × 30cm. We checked the range-shifter modelling from open-beam data. We tested clinical cases with film and an ionization chamber array (IBA Matrix).
Sigma differences for spots fitted using 2D images and 1D profiles to elliptical and circular Gaussian models were below 0.22 mm. Differences between SOBP measurements at single points and TPS calculations for all fields between 5 × 5 and 30 × 30cm were below 2.3%. Smaller fields had larger differences: up to 3.8% in the 2 × 2cm field. Mean differences at several depths along the central axis were generally below 1%. Differences in range-shifter doses were below 2.4%. Gamma test (3%, 3 mm) results for clinical cases were generally above 95% for Matrix and film.
Approaches for modelling synchrotron proton beams have been validated. Dose values for open and range-shifter fields demonstrate accurate Monte Carlo correction for IDDs. Elliptical spots can be successfully modelled using a circular Gaussian, which is accurate for patient calculations and can be used for small fields. A double-Gaussian spot can improve small-field calculations. The range-shifter modelling approach, which reduces clinical commissioning time, is adequate.
•Novel configuration: synchrotron-based proton therapy system with a Monte Carlo TPS.•The Monte Carlo-based correction applied by the TPS to the measured IDD is validated.•The single Gaussian modelling for the synchrotron physical spot is investigated.•Modelling of the range shifter with one set of measurements in open beams is checked.•The Monte Carlo dose calculation model performance in small fields is studied.
The biocatalytic synthesis of oxygenated biofuels (fatty acid solketal esters, FASEs) and biodiesel (fatty acid methyl esters, FAMEs) was carried out by both the direct esterification of fatty acids ...(i.e., lauric, myristic, palmitic, and oleic acids, respectively) with solketal or methanol, and the transesterification of vegetable oils (i.e. sunflower, olive, cottonseeds, and waste cooking oil) with the same alcohols, in hydrophobic ionic liquids (ILs) based on cations with long alkyl side-chains (e.g., octadecyltrimethylammonium bis(trifluoromethylsulfonyl)imide C18tmaNTf2). These hydrophobic ILs are temperature switchable ionic liquid/solid phases that behave as sponge-like system. As liquid phases, they are excellent monophasic reaction media for proposed biotransformations with all the assayed fat substrates, e.g. near to 100% yield of fatty acids solketyl esters (FASEs) and fatty acid methyl esters (FAMEs) in 6 h at 60 °C. By using waste cooking oil mixed with free fatty acids as substrate, green biofuels containing either both FAMEs and FASEs (e.g., aprox. 80% FAMEs and 20% FASEs, etc.) can easily be prepared. Moreover, the reaction mixture can be easily fractionated by iterative centrifugations at controlled temperature into three phases, i.e. solid IL, water, and FAMEs + FASEs mixture leading to a straightforward and clean approach allowing the full recovery of the biocatalyst/IL system for further reuse and the simple product isolation. Furthermore, the enzyme did not shown any loss in activity during reuse in these reaction systems after six operation cycles.
•Machinery positioning systems might super from loss of GNSS (Global Navigation Satellite System) signal.•New localization strategies become needed to fulfil the agricultural task.•This work analizes ...the usability of five well known scan matching algorithms as sole localization systems using a 2D LiDAR.•The system is tested in Chilean avocado groves where slippage is likely to occur.•Statistical results showing the pros and cons of scan matching techniques are included.
When working in agricultural environments, specially in groves with dense foliage, machinery positioning systems might suffer from loss of GNSS (Global Navigation Satellite System) signal. The latter motivated the development of new localization strategies that use the environment information to localize the machinery and thus fulfil the required agricultural task. In this work, the usability of five well known scan matching algorithms as sole localization systems using a 2D LiDAR (Light Detection and Ranging) scanner is tested in an avocado grove. The aim is to show the pros and cons of such techniques when the machinery faces a real agricultural environment: presence of slippage, absence of GNSS signal, non-flat terrains in a non-experimental grove and noisy LiDAR readings. The analysis presented herein concludes with a localization error evaluation when the machinery has to travel through a rough avocado alley, showing that amongst all the techniques implemented, the Probabilistic Iterative Correspondence (PIC) and the Sum of Gaussian Scan Correlation (SGSC) presented the lowest localization estimation error and remained consistent from a localization point of view.
Surrogacy is beginning to generate public debate, and the way the media approach it may have negative effects on social attitudes toward gay parenting. The news media play a key role in informing ...society, especially about topics such as surrogacy, of which most audiences have no direct experience. The aim of our research is to explore opinion formation of surrogacy and gay parenting by analyzing the audience interpretation of a TV news story in Spain. To do this we conducted four focus groups that were analyzed using a qualitative content analysis based on the discourse produced by the participants. The results show that the framing strategies used in the news story contribute to advocating an attitude of repudiation toward surrogacy, with an adverse sentiment also extending to homosexual couples who wish to become parents. This leads us to discuss the role of media in shaping public opinion and the resulting potential consequences in the case of surrogacy and gay parenting.
Automated pheromone dispensers disrupt the mating behaviour of pest moths by releasing pheromone during their daily activity period, which is not the same for all target species. These periods ...usually occur in or close to night time and last just a few hours, so automated sampling devices are needed to characterize them. However, the commercially available automated models do not provide enough temporal resolution for characterizing the short diel periods of sexual activity of moths. Thus, we built and tested a relatively cheap and simple high-temporal-resolution image-sensor insect trap. It consisted of a Raspberry Pi computer with an infrared camera operated by open-source software and housed in a plastic box. The Raspberry Pi was powered by a solar panel and rechargeable battery that were mounted on a solid and weather-proof structure made of cheap materials. Pictures were downloaded by WiFi from the Raspberry's SD card to a computer. Six traps baited either with synthetic sex pheromone or with females of Grapholita molesta (Busk) were tested in the fi eld. The traps were sturdy, reliable and easy to use, taking pictures at 10 min intervals, 24 h a day for over two months. These pictures confirmed previous results regarding the period of sexual activity of the oriental fruit moth, which will aid in determining the optimal time for operating automated pheromone dispensers.
In this study, the evaluation of the accuracy and performance of a light detection and ranging (LIDAR) sensor for vegetation using distance and reflection measurements aiming to detect and ...discriminate maize plants and weeds from soil surface was done. The study continues a previous work carried out in a maize field in Spain with a LIDAR sensor using exclusively one index, the height profile. The current system uses a combination of the two mentioned indexes. The experiment was carried out in a maize field at growth stage 12-14, at 16 different locations selected to represent the widest possible density of three weeds: Echinochloa crus-galli (L.) P.Beauv., Lamium purpureum L., Galium aparine L.and Veronica persica Poir.. A terrestrial LIDAR sensor was mounted on a tripod pointing to the inter-row area, with its horizontal axis and the field of view pointing vertically downwards to the ground, scanning a vertical plane with the potential presence of vegetation. Immediately after the LIDAR data acquisition (distances and reflection measurements), actual heights of plants were estimated using an appropriate methodology. For that purpose, digital images were taken of each sampled area. Data showed a high correlation between LIDAR measured height and actual plant heights (R2 = 0.75). Binary logistic regression between weed presence/absence and the sensor readings (LIDAR height and reflection values) was used to validate the accuracy of the sensor. This permitted the discrimination of vegetation from the ground with an accuracy of up to 95%. In addition, a Canonical Discrimination Analysis (CDA) was able to discriminate mostly between soil and vegetation and, to a far lesser extent, between crop and weeds. The studied methodology arises as a good system for weed detection, which in combination with other principles, such as vision-based technologies, could improve the efficiency and accuracy of herbicide spraying.
The use of a low-cost tractor-mounted scanning Light Detection and Ranging (LIDAR) system for capable of making non-destructive recordings of tree-row structure in orchards and vineyards is ...described. Field tests consisted of several LIDAR measurements on both sides of the crop row, before and after defoliation of selected trees. Summary parameters describing the tree-row volume and the total crop surface area viewed by the LIDAR (expressed as a ratio with ground surface area) were derived using a suitable numerical algorithm. The results for apple and pear orchards and a wine producing vineyard were shown to be in reasonable agreement with the results derived from a destructive leaf sampling method. Also, good correlation was found between manual and sensor-based measurements of the vegetative volume of tree-row plantations. The Tree Area Index parameter, TAI, gave the best correlation between destructive and non-destructive (i.e. LIDAR-based) determinants of crop leaf area. The LIDAR system proved to be a powerful technique for low cost, prompt and non-destructive estimates of the volume and leaf-area characteristics of plants.
Telaprevir for Retreatment of HCV Infection Zeuzem, Stefan; Andreone, Pietro; Pol, Stanislas ...
The New England journal of medicine,
06/2011, Letnik:
364, Številka:
25
Journal Article
Recenzirano
Odprti dostop
In patients with HCV infection who did not have a sustained response to peginterferon plus ribavirin, the addition of telaprevir to this combination therapy was more effective than combination ...therapy alone. Adverse events with telaprevir included rash and anemia.
Approximately 60% of patients who are infected with hepatitis C virus (HCV) genotype 1 are not cured by 48 weeks of peginterferon alfa combined with ribavirin.
1
Such patients fall into one of three categories: those who have no response to therapy, which is defined as a reduction of less than 2 log
10
in HCV RNA levels after 12 weeks of therapy
2
; those who have a partial response, which is defined as a reduction of at least 2 log
10
in a patient who has always had detectable serum HCV RNA during therapy; and those who have a relapse, . . .
PDF
