A calorimeter coupled with a magnetic spectrometer for the detection of primary cosmic antiprotons

A tracking calorimeter made of 3200 brass streamer tubes together with 3200 pick-up strips has been built to complement a magnetic spectrometer in order to detect cosmic antiprotons in space. The characteristics of such a calorimeter, the results of a preliminary test of a prototype as well as the properties of the whole apparatus are presented. The apparatus, designed to operate on a balloon at an altitude of about 40 km, can be considered as a second generation detector, capable in principle to solve the problem of the presence of low energy (≤1 Ge V/c) antiprotons in the cosmic rays which is still open because of the disagreement between the existent experimental data

Dosimetric characterization with 62 MeV protons of a silicon-segmented detector for 2D dose verifications in radiotherapy

Abstract Due to the features of the modern radiotherapy techniques, namely intensity modulated radiation therapy and proton therapy, where high spatial dose gradients are often present, detectors to be employed for 2D dose verifications have to satisfy very narrow requirements. In particular they have to show high spatial resolution. In the framework of the European Integrated Project—Methods and Advanced Equipment for Simulation and Treatment in Radio-Oncology (MAESTRO, no. LSHC-CT-2004-503564), a dosimetric detector adequate for 2D pre-treatment dose verifications was developed. It is a modular detector, based on a monolithic silicon-segmented sensor, with an n-type implantation on an epitaxial p-type layer. Each pixel element is 2×2 mm 2 and the distance center-to-center is 3 mm. The sensor is composed of 21×21 pixels. In this paper, we report the dosimetric characterization of the system with a proton beam. The sensor was irradiated with 62 MeV protons for clinical treatments at INFN-Laboratori Nazionali del Sud (LNS) Catania. The studied parameters were repeatability of a same pixel, response linearity versus absorbed dose, and dose rate and dependence on field size. The obtained results are promising since the performances are within the project specifications

Site-specific genetic engineering of the Anopheles gambiae Y chromosome.

Despite its function in sex determination and its role in driving genome evolution, the Y chromosome remains poorly understood in most species. Y chromosomes are gene-poor, repeat-rich and largely heterochromatic and therefore represent a difficult target for genetic engineering. The Y chromosome of the human malaria vector Anopheles gambiae appears to be involved in sex determination although very little is known about both its structure and function. Here, we characterize a transgenic strain of this mosquito species, obtained by transposon-mediated integration of a transgene construct onto the Y chromosome. Using meganuclease-induced homologous repair we introduce a site-specific recombination signal onto the Y chromosome and show that the resulting docking line can be used for secondary integration. To demonstrate its utility, we study the activity of a germ-line-specific promoter when located on the Y chromosome. We also show that Y-linked fluorescent transgenes allow automated sex separation of this important vector species, providing the means to generate large single-sex populations. Our findings will aid studies of sex chromosome function and enable the development of male-exclusive genetic traits for vector control

Atrial fibrillation pattern, left atrial diameter and risk of cardiovascular events and mortality. A prospective multicenter cohort study.

BACKGROUND There are conflicting evidence on the association between atrial fibrillation (AF) pattern, such as persistent/permanent (Pers/Perm) and paroxysmal (PAF) AF and risk of ischemic events. We investigated if left atrial diameter (LAd) may affect the risk of cardiovascular outcomes according to AF pattern. METHODS Prospective multicenter observational including 1,252 non-valvular AF patients (533 PAF and 719 Pers/Perm AF). Study endpoints were cardiovascular events (CVEs), major adverse cardiac events (MACE) and CV death. LA anteroposterior diameter (LAd) was obtained by transthoracic echocardiography. RESULTS Pers/Perm AF patients had a higher proportion of LAd above median than PAF (≥44 mm, 59.5% vs 37.5% respectively, P < .001). In a mean follow-up of 42.2 ± 31.0 months (4,315 patients/year) 179 CVEs (incidence rate [IR] 4.2%/year), 133 MACE (IR 3.1%/year), and 97 CV deaths (IR 2.2%/year) occurred. Compared to patients with LAd below median, those with LAd above the median had a higher rate of CVEs (log-rank test, P < .001), MACE (log-rank test P < .001), and CV death (log-rank test P < .001). Multivariable Cox regression analysis showed that LAd above the median was associated with CVEs, (HR 1.569, 95% CI 1.129-2.180, P = .007) MACE (HR 1.858, 95% CI 1.257-2.745, P = .002) and CV death (HR 2.106, 95% CI 1.308-3.390, P = .002). The association between LAd and outcomes was evident both in PAF and Pers/Perm AF patients. No association between AF pattern and outcomes was found. CONCLUSION LAd is a simple parameter that can be obtained in virtually all AF patients and can provide prognostic information on the risk of CVEs, MACE and CV death regardless of AF pattern

Comparison of anticoagulation quality between acenocoumarol and warfarin in patients with mechanical prosthetic heart valves. insights from the nationwide plectrum study

Vitamin K antagonists are indicated for the thromboprophylaxis in patients with mechanical prosthetic heart valves (MPHV). However, it is unclear whether some differences between acenocoumarol and warfarin in terms of anticoagulation quality do exist. We included 2111 MPHV patients included in the nationwide PLECTRUM registry. We evaluated anticoagulation quality by the time in therapeutic range (TiTR). Factors associated with acenocoumarol use and with low TiTR were investigated by multivariable logistic regression analysis. Mean age was 56.8 ± 12.3 years; 44.6% of patients were women and 395 patients were on acenocoumarol. A multivariable logistic regression analysis showed that patients on acenocoumarol had more comorbidities (i.e., ≥3, odds ratio (OR) 1.443, 95% confidence interval (CI) 1.081-1.927, p = 0.013). The mean TiTR was lower in the acenocoumarol than in the warfarin group (56.1 ± 19.2% vs. 61.6 ± 19.4%, p &lt; 0.001). A higher prevalence of TiTR (&lt;60%, &lt;65%, or &lt;70%) was found in acenocoumarol users than in warfarin ones (p &lt; 0.001 for all comparisons). Acenocoumarol use was associated with low TiTR regardless of the cutoff used at multivariable analysis. A lower TiTR on acenocoumarol was found in all subgroups of patients analyzed according to sex, hypertension, diabetes, age, valve site, atrial fibrillation, and INR range. In conclusion, anticoagulation quality was consistently lower in MPHV patients on acenocoumarol compared to those on warfarin

Full Geant4 and FLUKA Simulations of an e-LINAC for its Use in Particle Detectors Performance Tests

In this work we present the results of full Geant4 and FLUKA simulations and comparison with dosimetry data of an electron LINAC of St. Maria Hospital located in Terni, Italy. The facility is being used primarily for radiotherapy and the goal of present study is the detailed investigation of electron beam parameters to evaluate the possibility to use the e-LINAC (during time slots when it is not used for radiotherapy) to test the performance of detector systems in particular those designed to operate in space. The critical beam parameters are electron energy, profile and flux available at the surface of device to be tested. The present work aims to extract these parameters from dosimetry calibration data available at the e-LINAC. The electron energy ranges is from 4 MeV to 20 MeV. The dose measurements have been performed by using an Advanced Markus Chamber which has a small sensitive volume.Comment: 10 pages, 10 figures, 2 table

Efectos del tiempo de espera prefaena y la zona térmica en camión sobre la inmovilidad tónica en pollos parrilleros

La cadena de producción industrial de carne aviar incluye procedimientos que afectan el bienestar animal y consecuentemente la calidad del producto obtenido. Para evaluar el efecto del transporte y la manipulación pre-faena sobre el nivel de miedo en pollos, se han empleado pruebas de diferente tipo entre las cuales la inmovilidad tónica (IT) se destaca por su fácil determinación. El objetivo de este trabajo fue evaluar el efecto del tiempo de espera en playa de faena y la ubicación de la jaula en los camiones, sobre la duración de la IT en pollos parrilleros. El análisis comparativo se realizó mediante ANOVA en un arreglo factorial, tomándose como efectos principales el tiempo en playa de espera y la localización de la jaula en el camión. Se observaron diferencias estadísticamente significativas (p=0,0001) para IT, con valores de 248,88±12,86 s para el grupo espera larga y 167,88±13,4 s para espera corta. La zona térmica del camión también registró diferencias significativas (p=0,03) con valores de 189,06±14,74 s (zona ventilada) y 227,69±17,23 s (zona no ventilada). No se observaron diferencias significativas para el número de intentos de inducción a la inmovilidad en función del tiempo de espera y zona térmica del camión (p=0,08). No existieron correlaciones significativas entre las variables dependientes en ambos grupos experimentales. Los resultados de este trabajo permiten inferir que tiempos de espera en la playa pre-faena superiores a 3½ horas y altas temperaturas, provocan aumento en la duración de la IT, lo que la transforma en una herramienta útil para medir el estado de miedo de los pollos como consecuencia de ambas situacione

Low‐cost flexible thin‐film detector for medical dosimetry applications

The purpose of this study is to characterize dosimetric properties of thin film photovoltaic sensors as a platform for development of prototype dose verification equipment in radiotherapy. Towards this goal, flexible thin‐film sensors of dose with embedded data acquisition electronics and wireless data transmission are prototyped and tested in kV and MV photon beams. Fundamental dosimetric properties are determined in view of a specific application to dose verification in multiple planes or curved surfaces inside a phantom. Uniqueness of the new thin‐film sensors consists in their mechanical properties, low‐power operation, and low‐cost. They are thinner and more flexible than dosimetric films. In principle, each thin‐film sensor can be fabricated in any size (mm2 – cm2 areas) and shape. Individual sensors can be put together in an array of sensors spreading over large areas and yet being light. Photovoltaic mode of charge collection (of electrons and holes) does not require external electric field applied to the sensor, and this implies simplicity of data acquisition electronics and low power operation. The prototype device use for testing consists of several thin film dose sensors, each of about 1.5 cm×5 cm area, connected to simple readout electronics. Sensitivity of the sensors is determined per unit area and compared to EPID sensitivity, as well as other standard photodiodes. Each sensor independently measures dose and is based on commercially available flexible thin‐film aSi photodiodes. Readout electronics consists of an ultra low‐power microcontroller, radio frequency transmitter, and a low‐noise amplification circuit implemented on a flexible printed circuit board. Detector output is digitized and transmitted wirelessly to an external host computer where it is integrated and processed. A megavoltage medical linear accelerator (Varian Tx) equipped with kilovoltage online imaging system and a Cobalt source are use to irradiate different thin‐film detector sensors in a Solid Water phantom under various irradiation conditions. Different factors are considered in characterization of the device attributes: energies (80 kVp, 130 kVp, 6 MV, 15 MV), dose rates (different ms × mA, 100–600 MU/min), total doses (0.1 cGy‐500 cGy), depths (0.5 cm–20 cm), irradiation angles with respect to the detector surface (0°‐180°), and IMRT tests (closed MLC, sweeping gap). The detector response to MV radiation is both linear with total dose (~1‐400 cGy) and independent of dose rate (100‐600 Mu/min). The sensitivity per unit area of thin‐film sensors is lower than for aSi flat‐panel detectors, but sufficient to acquire stable and accurate signals during irradiations. The proposed thin‐film photodiode system has properties which make it promising for clinical dosimetry. Due to the mechanical flexibility of each sensor and readout electronics, low‐cost, and wireless data acquisition, it could be considered for quality assurance (e.g., IMRT, mechanical linac QA), as well as real‐time dose monitoring in challenging setup configurations, including large area and 3D detection (multiple planes or curved surfaces). PACS number: 87.56.F

Efectos del tiempo de espera prefaena y la zona térmica en camión sobre la inmovilidad tónica en pollos parrilleros

La cadena de producción industrial de carne aviar incluye procedimientos que afectan el bienestar animal y consecuentemente la calidad del producto obtenido. Para evaluar el efecto del transporte y la manipulación pre-faena sobre el nivel de miedo en pollos, se han empleado pruebas de diferente tipo entre las cuales la inmovilidad tónica (IT) se destaca por su fácil determinación. El objetivo de este trabajo fue evaluar el efecto del tiempo de espera en playa de faena y la ubicación de la jaula en los camiones, sobre la duración de la IT en pollos parrilleros. El análisis comparativo se realizó mediante ANOVA en un arreglo factorial, tomándose como efectos principales el tiempo en playa de espera y la localización de la jaula en el camión. Se observaron diferencias estadísticamente significativas (p=0,0001) para IT, con valores de 248,88±12,86 s para el grupo espera larga y 167,88±13,4 s para espera corta. La zona térmica del camión también registró diferencias significativas (p=0,03) con valores de 189,06±14,74 s (zona ventilada) y 227,69±17,23 s (zona no ventilada). No se observaron diferencias significativas para el número de intentos de inducción a la inmovilidad en función del tiempo de espera y zona térmica del camión (p=0,08). No existieron correlaciones significativas entre las variables dependientes en ambos grupos experimentales. Los resultados de este trabajo permiten inferir que tiempos de espera en la playa pre-faena superiores a 3½ horas y altas temperaturas, provocan aumento en la duración de la IT, lo que la transforma en una herramienta útil para medir el estado de miedo de los pollos como consecuencia de ambas situacionesTo evaluate the effect of transport and pre-slaughter manipulation on the level of fear in chickens, different tests have been used, among them tonic immobility (TI) stands out for its easy determination. The objective of this work was to evaluate the effect of pre-slaughter lairage time and the location of the cage in transport trucks on the duration of TI in broilers. The comparative analysis was done using ANOVA in a factorial arrangement, taking as main effects the time on pre-slaughter lairage periods and the location of the cage in the truck. There were statistically significant differences (p=0.0001) for TI, with values of 248.88±12.86 s and 167.88±13.4 s for the long and short waiting periods, respectively. The thermal area of the truck also showed significant differences (p=0.03) with values of 189.06±14.74 s (ventilated area) and 227.69±17.23 s (nonventilated area). There were no significant differences in the number of attempts to induce immobility as a function of the waiting time and the thermal area of the truck (p=0.08). There were no significant correlations between the dependent variables in both experimental groups. The waiting time on holding area greater than 3½ h and a higher temperature causes a longer duration of TI, making it a useful tool to measure the grade of fear of chickens as consequence of these situationsEEA ReconquistaFil: Gallard, Eliana Andrea. Instituto Nacional de Tecnología Agropecuaria (INTA). Estación Experimental Agropecuaria Reconquista; ArgentinaFil: Menichelli, Marcela Liliana. Instituto Nacional de Tecnología Agropecuaria (INTA). Estación Experimental Agropecuaria Reconquista; ArgentinaFil: Revidatti, Fernando. Universidad Nacional del Nordeste. Facultad de Ciencias Veterinarias. Cátedra Producción de Aves; ArgentinaFil: Fernandez, R.. Universidad Nacional del Nordeste. Facultad de Ciencias Veterinarias. Cátedra Producción de Aves; ArgentinaFil: Sanz, P. Universidad Nacional del Nordeste. Facultad de Ciencias Veterinarias. Cátedra Producción de Aves; Argentin

Data acquisition system for a proton imaging apparatus

New developments in the proton-therapy field for cancer treatments, leaded Italian physics researchers to realize a proton imaging apparatus consisting of a silicon microstrip tracker to reconstruct the proton trajectories and a calorimeter to measure their residual energy. For clinical requirements, the detectors used and the data acquisition system should be able to sustain about 1 MHz proton rate. The tracker read-out, using an ASICs developed by the collaboration, acquires the signals detector and sends data in parallel to an FPGA. The YAG:Ce calorimeter generates also the global trigger. The data acquisition system and the results obtained in the calibration phase are presented and discussed