Non-defensible middle ground for experimental realism: Why we are justified to believe in colored quarks

Experimental realism aims at striking a middle ground between scientific realism and anti-realism, between the success of experimental physics it would explain and the realism about scientific theories it would supplant. This middle ground reinstates the engineering idea that belief in scientific entities is justified on purely experimental grounds, without any commitment to scientific theories and laws. This paper argues that there is no defensible middle ground to be staked out when it comes to justifying physicists' belief in colored quarks, and that experimental realism shifts, under analysis, into scientific realism

Food waste materials appear efficient and low-cost adsorbents for the removal of organic and inorganic pollutants from wastewater

In recent studies, the adsorption capacity of several food waste materials has been assessed by performing adsorption experiments in heterogeneous operating conditions. In a latest study, the efficiency of such food waste materials for the removal of metals and metalloids from complex multi-element solutions was evaluated in homogeneous experimental conditions, which allowed comparing the adsorption capacities of the individual adsorbents. Considering the high efficiency of the examined low-cost adsorbents for the removal of inorganic pollutants, preliminary studies were conducted in our lab for assessing the potential of the investigated food waste materials to adsorb volatile organic compounds from a real polluted matrix of leachate. Some recent studies have shown the efficiency of low cost materials for the removal of industrial organic dyes, polycyclic aromatic hydrocarbons and phenolic compounds. However, the food waste adsorbents’ efficiency for the removal of volatile organic compounds was not investigated. Our preliminary studies showed good adsorption capacities of the examined food waste materials for aliphatic and aromatic hydrocarbons. Therefore, it is worth to carry out further studies about volatile organic compounds’ removal by food waste adsorbents

Nitric oxide alleviates cadmium- but not arsenic-induced damages in rice roots

Nitric oxide (NO) has signalling roles in plant stress responses. Cadmium (Cd) and arsenic (As) soil pollutants alter plant development, mainly the root-system, by increasing NO-content, triggering reactive oxygen species (ROS), and forming peroxynitrite by NO-reaction with the superoxide anion. Interactions of NO with ROS and peroxynitrite seem important for plant tolerance to heavy metal(oid)s, but the mechanisms underlying this process remain unclear. Our goal was to investigate NO-involvement in rice (Oryza sativa L.) root-system after exposure to Cd or As, to highlight possible differences in NO-behaviour between the two pollutants. To the aim, morpho-histological, chemical and epifluorescence analyses were carried out on roots of different origin in the root-system, under exposure to Cd or As, combined or not with sodium nitroprusside (SNP), a NO-donor compound. Results show that increased intracellular NO levels alleviate the root-system alterations induced by Cd, i.e., inhibition of adventitious root elongation and lateral root formation, increment in lignin deposition in the sclerenchyma/endodermis cell-walls, but, even if reducing As-induced endodermis lignification, do not recover the majority of the As-damages, i.e., enhancement of AR-elongation, reduction of LR-formation, anomalous tissue-proliferation. However, NO decreases both Cd and As uptake, without affecting the pollutants translocation-capability from roots to shoots. Moreover, NO reduces the Cd-induced, but not the As-induced, ROS levels by triggering peroxynitrite production. Altogether, results highlight a different behaviour of NO in modulating rice root-system response to the toxicity of the heavy metal Cd and the metalloid As, which depends by the NO-interaction with the specific pollutant

MULTISCALE DOCUMENTATION AND MONITORING OF L'AQUILA HISTORICALCENTRE USING UAV PHOTOGRAMMETRY

Nowadays geomatic techniques can guarantee not only a precise and accurate survey for the documentation of our historical heritage but also a solution to monitor its behaviour over time after, for example, a catastrophic event (earthquakes, landslides, ecc). Europe is trying to move towards harmonized actions to store information on cultural heritage (MIBAC with the ICCS forms, English heritage with the MIDAS scheme, etc) but it would be important to provide standardized methods in order to perform measuring operations to collect certified metric data. The final result could be a database to support the entire management of the cultural heritage and also a checklist of "what to do" and "when to do it". The wide range of geomatic techniques provides many solutions to acquire, to organize and to manage data at a multiscale level: high resolution satellite images can provide information in a short time during the "early emergency" while UAV photogrammetry and laser scanning can provide digital high resolution 3D models of buildings, ortophotos of roofs and facades and so on. This paper presents some multiscale survey case studies using UAV photogrammetry: from a minor historical village (Aielli) to the centre of L'Aquila (Santa Maria di Collemaggio Church) from the post-emergency to now. This choice has been taken not only to present how geomatics is an effective science for modelling but also to present a complete and reliable way to perform conservation and/or restoration through precise monitoring techniques, as shown in the third case study

Improved visualization of X-ray phase contrast volumetric data through artifact-free integrated differential images

Artifacts arising when differential phase images are integrated is a common problem to several X-ray phase-based experimental techniques. The combination of noise and insufficient sampling of the high-frequency differential phase signal leads to the formation of streak artifacts in the projections, translating into poor image quality in the tomography slices. In this work, we apply a non-iterative integration algorithm proven to reduce streak artifacts in planar (2D) images to a differential phase tomography scan. We report on how the reduction of streak artifacts in the projections improves the quality of the tomography slices, especially in the directions different from the reconstruction plane. Importantly, the method is compatible with large tomography datasets in terms of computation time

Aspirin-dependent effects on purinergic P2Y1 receptor express

Chronic treatment with aspirin in healthy volunteers (HVs) is associated with recovery of adenosine diphosphate (ADP)-induced platelet activation. The purinergic P2Y1 receptor exerts its effects via a Gq-protein, which is the same biochemical pathway activated by thromboxane-A2 receptor. We hypothesized that recovery of ADP-induced platelet activation could be attributed to increased P2Y1 expression induced by chronic aspirin exposure. We performed a multi-phase investigation which embraced both in vitro and in vivo experiments conducted in (1) human megakaryoblastic DAMI cells, (2) human megakaryocytic progenitor cell cultures, (3) platelets obtained from HVs treated with aspirin and (4) platelets obtained from aspirin-treated patients. DAMI cells treated with aspirin or WY14643 (PPARα agonist) had a significant up-regulation of P2Y1 mRNA, which was shown to be a PPARα-dependent process. In human megakaryocytic progenitors, in the presence of aspirin or WY14643, P2Y1 mRNA expression was higher than in mock culture. P2Y1 expression increased in platelets obtained from HVs treated with aspirin for 8 weeks. Platelets obtained from patients who were on aspirin for more than 2 months had increased P2Y1 expression and ADP-induced aggregation compared with patients on aspirin treatment for less than a month. Overall, our results suggest that aspirin induces genomic changes in megakaryocytes leading to P2Y1 up-regulation and that PPARα is the nuclear receptor involved in this regulation. Since P2Y1 is coupled to the same Gq-protein of thromboxane-A2 receptor, platelet adaptation in response to pharmacological inhibition seems not to be receptor specific, but may involve other receptors with the same biochemical pathway

Evaluation of a compact multi-contrast and multi-resolution X-ray phase contrast edge illumination system for small animal imaging

PURPOSE: In this work the performance of a compact multi-resolution and multi-contrast X-ray phase system based on edge illumination is investigated. It has been designed for small animal imaging and with a limited footprint for ease of deployment in laboratories. METHODS: The presented edge illumination system is based on a compact microfocus tungsten X-ray source combined with a at panel detector. The source has a maximum output of 10 W when the minimum spot size of about 15 µm is used. The system has an overall length of 70 cm. A new double sample mask design, obtained by arranging both skipped and non-skipped configurations on the same structure, provides dual resolution capability. To test the system, we carried out CT scans of a plastic phantom with different source settings using both single-image and multi-image acquisition schemes at different spatial resolutions. In addition, CT scans of an ex-vivo mouse specimen were acquired at the best identified working conditions to demonstrate the application of the presented system to small animal imaging. RESULTS: We found this system delivers good image quality, allowing for an efficient material separation and improving detail visibility in small animals thanks to the higher signal-to-noise ratio (SNR) of phase contrast with respect to conventional attenuation contrast. The system offers high versatility in terms of spatial resolution thanks to the double sample mask design integrated into a single scanner. The availability of both multi and single image acquisition schemes coupled with their dedicated retrieval algorithms, allows different working modes which can be selected based on user preference. Multi-image acquisition provides quantitative separation of the real and imaginary part of the refractive index, however it requires a long scanning time. On the other hand, the single image approach delivers the best material separation and image quality at all the investigated source settings with a shorter scanning time but at the cost of quantitativeness. Finally, we also observed that the single image approach combined with a high-power X-ray source may result in a fast acquisition protocol compatible with in-vivo imaging

The transition from refraction to Ultra-Small-Angle X-ray Scattering (USAXS) in a laboratory phase-based X-ray microscope for soft tissue imaging

We report on a laboratory-based x-ray microscope allowing for phase-contrast imaging of soft tissue samples. The used beam tracking approach allows retrieval of Ultra-Small-Angle X-ray Scattering (USAXS) or dark field alongside attenuation and differential phase. We show the dependence of the refraction and dark field signal on the size of the imaged features. The application of the technique to a biological sample is also demonstrated