ABSTRACT In recent years, the increasing precision of direct cosmic rays measurements opened the door to high-sensitivity indirect searches of dark matter and to more accurate predictions for ...radiation doses received by astronauts and electronics in space. The key ingredients in the study of these phenomena are the knowledge of the local interstellar spectrum (LIS) of galactic cosmic rays and the understanding of how the solar modulation affects the LIS inside the heliosphere. Voyager 1, AMS-02, PAMELA, and BESS measurements of proton and helium fluxes provide valuable information, allowing us to shed light on the shape of the LIS and the details of the solar modulation during solar cycles 22-24. A new parametrization of the LIS is presented, based on the latest data from Voyager 1 and AMS-02. Using the framework of the force-field approximation, the solar modulation parameter is extracted from the time-dependent fluxes measured by PAMELA and BESS. A modified version of the force-field approximation with a rigidity-dependent modulation parameter is introduced, yielding better fits than the force-field approximation. The results are compared with the modulation parameter inferred by neutron monitors.
Acute GvHD (aGvHD) is the main complication of hematopoietic SCT (HSCT) during the treatment of hematological disorders. We carried out the first longitudinal study to follow the gut microbiota ...trajectory, from both the phylogenetic and functional points of view, in pediatric patients undergoing HSCT. Gut microbiota trajectories and short-chain fatty acid production profiles were followed starting from before HSCT and through the 3-4 months after transplant in children developing and not developing aGvHD. According to our findings, HSCT procedures temporarily cause a structural and functional disruption of the gut microbial ecosystem, describing a trajectory of recovery during the following 100 days. The onset of aGvHD is associated with specific gut microbiota signatures both along the course of gut microbiota reconstruction immediately after transplant and, most interestingly, prior to HSCT. Indeed, in pre-HSCT samples, non-aGvHD patients showed higher abundances of propionate-producing Bacteroidetes, highly adaptable microbiome mutualists that showed to persist during the HSCT-induced ecosystem disruption. Our data indicate that structure and temporal dynamics of the gut microbial ecosystem can be a relevant factor for the success of HSCT and opens the perspective to the manipulation of the pre-HSCT gut microbiota configuration to favor mutualistic persisters with immunomodulatory properties in the gut.
A new era in cosmic rays physics has started thanks to the precise and continuous observations from space experiments such as PAMELA and AMS-02. Invaluable results are coming out from these new data ...that are rewriting the theory of acceleration and propagation of cosmic rays. Both at high energies, where several new behaviors have been measured, challenging the accuracy of theoretical models, and also at low energies, in the region affected by the solar modulation. Precise measurements are increasing our knowledge of the effects of solar modulation on low energy cosmic rays, allowing a detailed study of propagation and composition as it has never been done before. These measurements will serve as a high-precision baseline for continued studies of GCR composition, GCR modulation over the solar cycle, space radiation hazards, and other topics.
In this review paper, the status of the latest measurements of the cosmic rays in the context of solar modulation are presented together with the current open questions and the future prospects. How new measurements from the AMS-02 experiment will address these questions is also discussed.
Epidemiological and experimental observations suggest that chronic microbial colonization can impact the immune control of other unrelated pathogens contracted in a concomitant or sequential manner. ...Possible interactions between Mycobacterium tuberculosis infection and persistence of other bacteria have scarcely been investigated. Here we demonstrated that natural colonization of the digestive tract with Helicobacter hepaticus in mice is concomitant with modification of the gut microbiota, subclinical inflammation, and drastic impairment of immune control of the growth of subsequently administered M. tuberculosis, which results in severe lung tissue injury. Our results provided insights upon the fact that this prior H. hepaticus colonization leads to failures in the mechanisms that could prevent the otherwise balanced cross-talk between M. tuberculosis and the immune system. Such disequilibrium ultimately leads to the inhibition of control of mycobacterial growth, outbreak of inflammation, and lung pathology. Among the dysregulated immune signatures, we noticed a correlation between the detrimental lung injury and the accumulation of activated T-lymphocytes. Our findings suggest that the impact of prior Helicobacter spp. colonization and subsequent M. tuberculosis parasitism might be greater than previously thought, which is a key point given that both species are among the most frequent invasive bacteria in human populations.
A propagation model of galactic cosmic protons through the heliosphere was implemented using a two-dimensional Monte Carlo approach to determine the differential intensities of protons during solar ...cycle 23. The model includes the effects due to the variation of solar activity during the propagation of cosmic rays from the boundary of the heliopause down to Earth's position. Drift effects are also accounted for. The simulated spectra were found to be in agreement with those obtained from experimental observations carried out by the BESS, AMS, and PAMELA collaborations. In addition, the modulated spectrum determined with the present code for the year 1995 exhibits the latitudinal gradient and equatorial southward offset minimum found by the Ulysses fast scan in 1995.
A specific 'adipose tissue' microbiota has been recently identified in mice and hypothesized in humans. The purpose of this study was to verify the presence of microbiota of human whole adipose ...tissue and isolated adipocytes by combining culture-dependent and independent methods.
Standard microbiological cultural techniques and 16S ribosomal RNA (16S rRNA) gene sequencing (Illumina technology) on DNA and RNA were employed to study (a) whole abdominal subcutaneous adipose tissue (SAT) and visceral adipose tissue (VAT) from 14 obese and five normal-weight subjects and (b) mature adipocytes isolated from SAT and VAT after collagenase digestion or mechanical separation. To optimize the 16S rRNA gene detection, we used different DNA extraction methods (lysis with proteinase K, proteinase K+lysozyme and microbeads) and amplification procedures (semi-quantitative standard PCR and real-time quantitative PCR).
Microbiological cultures were negative in all analyzed samples. In enzymatically isolated adipocytes, 90% of the sequenced bacterial DNA belonged to Clostridium histolyticum, the bacterium from which the collagenase enzyme was isolated. Bacterial 16S rRNA gene was not detected from DNA and RNA of whole SAT and VAT, as well as of mechanically isolated mature adipocytes, even after blocking with a specific primer the nonspecific amplification of human mitochondrial 12S rRNA.
Our results do not support the presence of a human adipose tissue microbiota. In addition, they emphasized the technical problems encountered when applying metagenomic studies to human tissues with very low or absent bacterial load.
This paper describes a new DNA chip, based on the use of a ligation detection reaction coupled to a universal array, developed to detect and analyze, directly from milk samples, microbial pathogens ...known to cause bovine, ovine, and caprine mastitis or to be responsible for foodborne intoxication or infection, or both. Probes were designed for the identification of 15 different bacterial groups: Staphylococcus aureus, Streptococcus agalactiae, nonaureus staphylococci, Streptococcus bovis, Streptococcus equi, Streptococcus canis, Streptococcus dysgalactiae, Streptococcus parauberis, Streptococcus uberis, Streptococcus pyogenes, Mycoplasma spp., Salmonella spp., Bacillus spp., Campylobacter spp., and Escherichia coli and related species. These groups were identified based on the 16S rRNA gene. For microarray validation, 22 strains from the American Type Culture Collection or other culture collections and 50 milk samples were tested. The results demonstrated high specificity, with sensitivity as low as 6 fmol. Moreover, the ligation detection reaction-universal array assay allowed for the identification of Mycoplasma spp. in a few hours, avoiding the long incubation times of traditional microbiological identification methods. The universal array described here is a versatile tool able to identify milk pathogens efficiently and rapidly.
The actual and next decade will be characterized by an exponential increase in the Beyond Low Earth Orbit space exploration. In this context, a detailed space radiation field characterization will be ...crucial to optimize radioprotection strategies, assess the risk of the health hazard related to human space exploration, and reduce the damages potentially induced to astronauts from galactic cosmic radiation. Since the beginning of the century, many astroparticle experiments investigating the unknown universe components (e.g., dark matter, antimatter, dark energy) have collected enormous amounts of data regarding the cosmic ray (CR) components of the radiation in space. Such experiments are CR observatories, and the collected CR events contain valuable information that can enhance the space radiation field characterization. This paper will briefly present the status of the art of this research topic, and a research initiative titled “Astroparticle Experiments to Improve the Biological Risk Assessment of Exposure to Ionizing Radiation in the Exploratory Space Missions” will be introduced.
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•Crewed space missions in the deep space region are planned in these days.•Space radiation characterization is crucial to assess the risk of the health hazard.•Many astroparticle experiments measure with accuracy the Cosmic Rays components.•Such data could an can be used to improve the space radiobiology knowledge.•We promoted a research topic to foster synergies between these two research areas.
The objective of this study was to develop and validate a fast method for typing the main mutations of bovine milk protein genes by using microarray technology. An approach based on the ligation ...detection reaction (LDR) and a universal array (UA) was used. Polymorphisms in both the coding and noncoding sequences of αS1-casein, β-casein, κ-casein, and β-lactoglobulin genes were considered because of their well-known effects on milk composition and cheese production. A total of 22 polymorphic sites, corresponding to 21 different variants, were included in the diagnostic microarray. First, a multiplex PCR was developed to amplify all the DNA target sequences simultaneously. Second, the LDR-UA assay was implemented. The method was validated by analyzing 100 Italian Friesian DNA samples, which were also genotyped by conventional methods both at the protein level by means of milk isoelectrofocusing and at the molecular level using PCR-RFLP and PCR-single strand conformation polymorphism techniques. The genotypes obtained using the LDR-UA approach were in full agreement with those obtained by the conventional analyses. An important result of the LDR-UA assay was a more accurate genotyping of the different milk protein alleles than was found with conventional typing methods. At the κ-casein gene, in fact, 4 samples were heterozygous (3 reference samples and 1 validation sample) for an allele coding for Thr136 and Ala148. This variant, which can be considered as the wild type of the genus Bos, is not usually identifiable by the conventional typing methods used. The multiplex PCR-LDR-UA approach developed provides for an accurate, inexpensive, and high-throughput assay that does not exhibit false positive or false negative signals, thus making it highly suitable for animal genotyping.
In the present work, an improved numerical solution for determining the ratio, R Mott , of the unscreened Mott differential cross section (MDCS) with respect to Rutherford's formula is proposed for ...the scattering of electrons and positrons on nuclei with 1 <= Z <= 118 . It accounts for incoming lepton energies between 1 keV and 900 MeV. For both electrons and positrons, a fitting formula and a set of fitting coefficients for the ratio R Mott on nuclei are also presented. The found average error of the latter practical interpolated expression is typically lower than 1% also at low energy for electrons and lower than 0.05% for positrons for all nuclei over the entire energy range.
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