35 research outputs found

    The large scale polarization explorer (LSPE) for CMB measurements: performance forecast

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    The measurement of the polarization of the Cosmic Microwave Background (CMB) radiation is one of the current frontiers in cosmology. In particular, the detection of the primordial divergence-free component of the polarization field, the B-mode, could reveal the presence of gravitational waves in the early Universe. The detection of such a component is at the moment the most promising technique to probe the inflationary theory describing the very early evolution of the Universe. We present the updated performance forecast of the Large Scale Polarization Explorer (LSPE), a program dedicated to the measurement of the CMB polarization. LSPE is composed of two instruments: LSPE-Strip, a radiometer-based telescope on the ground in Tenerife-Teide observatory, and LSPE-SWIPE (Short-Wavelength Instrument for the Polarization Explorer) a bolometer-based instrument designed to fly on a winter arctic stratospheric long-duration balloon. The program is among the few dedicated to observation of the Northern Hemisphere, while most of the international effort is focused into ground-based observation in the Southern Hemisphere. Measurements are currently scheduled in Winter 2022/23 for LSPE-SWIPE, with a flight duration up to 15 days, and in Summer 2022 with two years observations for LSPE-Strip. We describe the main features of the two instruments, identifying the most critical aspects of the design, in terms of impact on the performance forecast. We estimate the expected sensitivity of each instrument and propagate their combined observing power to the sensitivity to cosmological parameters, including the effect of scanning strategy, component separation, residual foregrounds and partial sky coverage. We also set requirements on the control of the most critical systematic effects and describe techniques to mitigate their impact. LSPE will reach a sensitivity in tensor-to-scalar ratio of σr < 0.01, set an upper limit r < 0.015 at 95% confidence level, and improve constraints on other cosmological parameters

    The effect of mammalian lactogenic hormone on lower chordates

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    High frequency of non-Hodgkin&apos;s lymphoma in patients with HIV-associated Kaposi&apos;s sarcoma

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    Objective: To evaluate, with the support of autopsy findings, the frequency of non-Hodgkin's lymphoma (NHL) among patients with AIDS-associated Kaposi's sarcoma (KS) in comparison with that of AIDS patients with other AIDS-defining diseases. Methods: The study involved 363 consecutive patients with AIDS who were cared for and died at the Clinic of Infectious Diseases in Milan between May 1984 and December 1992. Clinical records and autopsy data of all of the patients were retrospectively reviewed. Kaplan-Meier product-limit estimates of the time to the development of NHL were calculated for all patients and by specific subgroups. Cox proportional hazards analyses were made to determine the factors associated with the development of NHL. Results: In the majority of cases (82%), KS was diagnosed during life, whereas NHL was diagnosed before death in only 41.6% of cases. Taking the autopsy data into account, the cumulative incidence of the two rumours was 16.8% for KS and 16.5% for NHL. Among the 61 patients in whom KS was the index disease of AIDS, 16 also developed NHL. The probability of developing NHL was significantly higher in patients with KS at AIDS diagnosis than in patients with Pneumocystis carinii pneumonia (PCP), oesophageal candidiasis or other AIDS-related diseases (P = 0.004). Multivariate analysis of the factors associated with the development of NHL (such as sex, age, risk factors, AIDS-defining diseases and CD4+ cell counts) showed that the patients with KS as the index disease of AIDS had a 5.3-fold higher risk of developing NHL than the patients with PCP as the primary manifestation of AIDS. Conclusions: Our results confirm the higher incidence of malignant lymphoma in patients with AIDS-KS than in patients with other AIDS-related diseases. The importance of autopsy in assessing these data is underlined by the high percentage of NHL diagnosed only after death. These observations may support the hypothesis of a common aetiological agent, or of a common pathway, for the two neoplasms
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