A precision measurement by the Alpha Magnetic Spectrometer on the International Space Station of the positron fraction in primary cosmic rays in the energy range from 0.5 to 350 GeV based on 6.8 × ...10(6) positron and electron events is presented. The very accurate data show that the positron fraction is steadily increasing from 10 to ∼ 250 GeV, but, from 20 to 250 GeV, the slope decreases by an order of magnitude. The positron fraction spectrum shows no fine structure, and the positron to electron ratio shows no observable anisotropy. Together, these features show the existence of new physical phenomena.
Hydrogenated amorphous silicon (a-Si:H) particle detectors have been considered as alternatives to crystalline silicon detectors (c-Si) in high radiation environments, due to their excellent ...radiation hardness. However, although their capability for particle flux measurement in beam monitoring applications is quite satisfactory, their minimum ionizing particle (MIP) detection has always been problematic because of the poor signal-to-noise ratio caused by a low charge collection efficiency and relatively high (compared to crystalline silicon) leakage current. In this article, after a review of the status of technological research for a-Si:H detectors, a perspective view on MIP detection and beam flux measurements with these detectors will be given.
The vertex detectors for the future hadronic colliders will operate under proton fluencies above 1016 p/cm2. Crystalline Silicon detector technology, up to now, has kept the pace of the increasing ...fluencies in the LHC era and it is still the prevalent vertex detector material for the present and for the immediate future. Looking ahead in time, an alternative solution for such a detector has to be found because for the future there is no guarantee that Crystalline Silicon will hold this challenge. For this reason the development of hydrogenated amorphous silicon vertex detectors based on 3D-technology have been proposed and the technological solutions in order to build these detectors are described in this paper.
The Alpha Magnetic Spectrometer (AMS) was flown on the space shuttle Discovery during flight STS-91 (June 1998) in a 51.7° orbit at altitudes between 320 and.A search for antihelium nuclei in the ...rigidity range 1–was performed. No antihelium nuclei were detected at any rigidity. An upper limit on the flux ratio of antihelium to helium of <1.1×10−6 was obtained.The high energy proton, electron, positron, helium, antiproton and deuterium spectra were accurately measured.For each particle and nuclei two distinct spectra were observed: a higher energy spectrum and a substantial second spectrum. Positrons in the second spectrum were found to be much more abundant than electrons. Tracing particles from the second spectra shows that most of them travel for an extended period of time in the geomagnetic field, and that the positive particles (p and e+) and negative ones (e−) originate from two complementary geographic regions. The second helium spectrum flux over the energy range 0.1–was measured to be . Over 90 percent of the helium flux was determined to be at the 90% confidence level. (Elsevier)
Introduction
Left ventricular (LV) end-systolic elastance (Ees) can be estimated using single-beat (Ees(sb)) Chen method, employing systolic and diastolic arm-cuff pressures, stroke volume (SV), ...ejection fraction and estimated normalized ventricular elastance at arterial end-diastole. This work aims to conduct a sensitivity analysis of Chen formula to verify its reliability and applicability in clinical scenario.
Methods
Starting from a baseline condition, we evaluated the sensitivity of Ees(sb) to the parameters contained in the formula. Moreover, a mathematical model of the cardiovascular system was used to evaluate the sensitivity of Ees(sb) to end-diastolic LV elastance (Eed), Ees, arterial systemic resistance (Ras) and heart rate (HR).
Results
In accordance with Ees definition, Ees(sb) increases by increasing aortic pressure and pre-ejection time, reaching the highest value for a pre-ejection time = 40 ms, and then decreases. In contrast with Ees definition, Ees(sb) increases (from 3.21 mmHg/mL to 12.15 mmHg/mL) by increasing the LV end-systolic volume and decreases by increasing the SV. In the majority of the analysis with the mathematical model, Ees was underestimated using the Chen method: by increasing Ees (from 0.5 to 2.5 mmHg/mL), Ees(sb) passes only from 0.56 to 1.54 mmHg/mL. Ees(sb) increases for higher Eed (from 1.03 to 2.33 mmHg/mL). Finally, Ees(sb) decreases (increases) for HR < 50 bpm (< 50 bpm), and for Ras < 1100 mmHg/gcm
4
(> 1100 mmHg/gcm
4
).
Conclusion
Unexpectedly Ees(sb) increases for higher LV end-systolic volume and decreases for higher SV. These results contrast with Ees definition, which is the ratio between the LV end-systolic pressure and the LV end-systolic volume. Moreover, Ees(sb) is influenced by cardiocirculatory parameters such as LV Eed, HR, Ras, ejection time, and pre-ejection time. Finally, Ees(sb) computed with the model output often underestimates model Ees.
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 situaciones
Pixel sensors have been calibrated using both fluorescence X-ray photons and an X-ray beam obtained by the transmission technique. The X-rays were generated by an Amptek EDIX 40 X-ray tube (maximum ...voltage 40kV). During the fluorescence calibration the pixel sensor was placed in front of the target in an off-beam position; the resulting photons hitting the detector were emitted by fluorescence in all directions with an energy which is typical of the fluorescence lines of the target material. During the calibration in the transmission mode the detector was placed behind the target, acting now as a filter, and the energy of the photons was tuned by adjusting the voltage of the tube and the thickness of the target. In this paper the comparison between the two methods will be shown. From the results of this test, it is possible to infer that transmission is more efficient (higher photon yield) and flexible (more energy points are possible) but produces broader spectral lines while fluorescence has a better energy definition. A reasonable strategy to benefit from both methods is using fluorescence to calibrate a spectrometer that will be used to evaluate the energy of the X-rays emitted in the transmission mode. The results of this calibration will be shown in this paper.
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.
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