PAMELA results on the cosmic-ray antiproton flux from 60 MeV to 180 GeV in kinetic energy

The satellite-borne experiment PAMELA has been used to make a new measurement of the cosmic-ray antiproton flux and the antiproton-to-proton flux ratio which extends previously published measurements down to 60 MeV and up to 180 GeV in kinetic energy. During 850 days of data acquisition approximately 1500 antiprotons were observed. The measurements are consistent with purely secondary production of antiprotons in the galaxy. More precise secondary production models are required for a complete interpretation of the results.Comment: 11 pages, 3 figures, 1 table. Accepted for publication in Physical Review Letter

Advanced optical imaging in living embryos

Developmental biology investigations have evolved from static studies of embryo anatomy and into dynamic studies of the genetic and cellular mechanisms responsible for shaping the embryo anatomy. With the advancement of fluorescent protein fusions, the ability to visualize and comprehend how thousands to millions of cells interact with one another to form tissues and organs in three dimensions (xyz) over time (t) is just beginning to be realized and exploited. In this review, we explore recent advances utilizing confocal and multi-photon time-lapse microscopy to capture gene expression, cell behavior, and embryo development. From choosing the appropriate fluorophore, to labeling strategy, to experimental set-up, and data pipeline handling, this review covers the various aspects related to acquiring and analyzing multi-dimensional data sets. These innovative techniques in multi-dimensional imaging and analysis can be applied across a number of fields in time and space including protein dynamics to cell biology to morphogenesis

Intracellular lumen extension requires ERM-1-dependent apical membrane expansion and AQP-8-mediated flux

SUMMARY Many unicellular tubes such as capillaries form lumens intracellularly, a process that is not well understood. Here we show that the cortical membrane organizer ERM-1 is required to expand the intracellular apical/lumenal membrane and its actin undercoat during single-cell C.elegans excretory canal morphogenesis. We characterize AQP-8, identified in an ERM-1 overexpression (ERM-1[++]) suppressor screen, as a canalicular aquaporin that interacts with ERM-1 in lumen extension in a mercury-sensitive manner, implicating water-channel activity. AQP-8 is transiently recruited to the lumen by ERM-1, co-localizing in peri-lumenal cuffs interspaced along expanding canals. An ERM-1[++]-mediated increase in the number of lumen-associated canaliculi is reversed by AQP-8 depletion. We propose that the ERM-1-AQP-8 interaction propels lumen extension by translumenal flux, suggesting a direct morphogenetic effect of water-channel-regulated fluid pressure

Tumor estrogen content and clinico-morphological and endocrine features of endometrial cancer

Objectives: To compare estrogen concentrations in endometrial cancer tissue with those in macroscopically normal endometrium and with certain morphological characteristics of the tumor and endocrine parameters in patients. Methods: The estradiol content was evaluated by radioimmunoassay after homogenization and extraction in 78 adenocarcinomas (61 from postmenopausal patients). Results: Higher concentrations of estradiol in tumor tissue samples than in macroscopically normal endometrium were found in patients of both reproductive and postmenopausal age. This difference was the same in patients with either endometrial carcinoma type I or type II. No association between tumor steroid receptor levels, estradiol concentrations in blood serum, and timing of menopause with intratumoral estradiol contents was discovered. Estradiol concentrations in tumor tissues correlated positively with the clinical stage of disease and rate of tumor invasion (in patients with peripheric/lower type of fat topography), and negatively with tumor differentiation stage (in patients with central/upper type of fat topography) and the percentage of intact double-stranded DNA in normal endometrium. Conclusions: Tumor estrogen content in endometrial cancer has clinical significance that is modified in the presence of certain endocrine characteristics related to insulin resistance. The role of local estrogen production (aromatase activity) in this setting deserves special study

Time Dependence of the electron and positron components of the cosmic radiation measured by the PAMELA experiment between July 2006 and December 2015

Cosmic-ray electrons and positrons are a unique probe of the propagation of cosmic rays as well as of the nature and distribution of particle sources in our Galaxy. Recent measurements of these particles are challenging our basic understanding of the mechanisms of production, acceleration, and propagation of cosmic rays. Particularly striking are the differences between the low energy results collected by the space-borne PAMELA and AMS-02 experiments and older measurements pointing to sign-charge dependence of the solar modulation of cosmic-ray spectra. The PAMELA experiment has been measuring the time variation of the positron and electron intensity at Earth from July 2006 to December 2015 covering the period for the minimum of solar cycle 23 (2006-2009) until the middle of the maximum of solar cycle 24, through the polarity reversal of the heliospheric magnetic field which took place between 2013 and 2014. The positron to electron ratio measured in this time period clearly shows a sign-charge dependence of the solar modulation introduced by particle drifts. These results provide the first clear and continuous observation of how drift effects on solar modulation have unfolded with time from solar minimum to solar maximum and their dependence on the particle rigidity and the cyclic polarity of the solar magnetic field

Unexpected Cyclic Behavior in Cosmic-Ray Protons Observed by PAMELA at 1 au

Protons detected by the PAMELA experiment in the period 2006-2014 have been analyzed in the energy range between 0.40-50 GV to explore possible periodicities besides the well known solar undecennial modulation. An unexpected clear and regular feature has been found at rigidities below 15 GV, with a quasi-periodicity of $\sim$450 days. A possible Jovian origin of this periodicity has been investigated in different ways. The results seem to favor a small but not negligible contribution to cosmic rays from the Jovian magnetosphere, even if other explanations cannot be excluded.Comment: article 4 figures, 1 tabl