Physics student ideas on quantum state and its formal representations

Developing a quantum way of thinking is a core and challenging task for physics students. The concept of quantum state, whose physical meaning is connected to the formal structure of the theory, plays an important role in the construction of a quantum perspective and in student difficulties elicited by research. A questionnaire and interview protocol were devised to explore student understanding of the state concept in connection to the properties of its formal representations and to quantum behavior. Results of a calibration of research instruments performed on 6 physics students from different universities are here presented

Compartmentalization of adenosine metabolism in cancer cells and its modulation during acute hypoxia.

Extracellular adenosine mediates diverse anti-inflammatory, angiogenic and vasoactive effects and becomes an important therapeutic target for cancer, which has been translated into clinical trials. This study was designed to comprehensively assess adenosine metabolism in prostate and breast cancer cells. We identified cellular adenosine turnover as a complex cascade, comprised of (a) the ectoenzymatic breakdown of ATP via sequential nucleotide pyrophosphatase/phosphodiesterase-1, ecto-5'-nucleotidase/CD73 and adenosine deaminase reactions, and ATP re-synthesis through counteracting adenylate kinase and nucleoside diphosphokinase; (b) the uptake of nucleotide-derived adenosine via equilibrative nucleoside transporters; and (c) the intracellular adenosine phosphorylation into ATP by adenosine kinase and other nucleotide kinases. The exposure of cancer cells to 1% O2 for 24 hours triggered ∼2-fold up-regulation of CD73, without affecting nucleoside transporters, adenosine kinase activity and cellular ATP content. The ability of adenosine to inhibit the tumor-initiating potential of breast cancer cells via receptor-independent mechanism was confirmed in vivo using a xenograft mouse model. The existence of redundant pathways controlling extracellular and intracellular adenosine provides a sufficient justification for reexamination of the current concepts of cellular purine homeostasis and signaling in cancer

Unresolved sources naturally contribute to PeV γ\gamma-ray diffuse emission observed by Tibet ASγ\gamma

The Tibet AS$\gamma$ experiment provided the first measurement of the total diffuse gamma-ray emission from the Galactic disk in the sub-PeV energy range. Based on the analysis of TeV sources included in the HGPS catalog, we predict the expected contribution of unresolved sources in the two angular windows of the Galactic plane observed by Tibet AS$\gamma$. We show that the sum of this additional diffuse component due to unresolved sources and the truly diffuse emission, due to cosmic ray interaction with the interstellar medium, well saturates the Tibet data, without the need to introduce a progressive hardening of the cosmic-ray spectrum toward the Galactic center

Low Rates of Pointing in 18-Month-Olds at Risk for Autism Spectrum Disorder and Extremely Preterm Infants: A Common Index of Language Delay?

Infants with an older sibling with an Autism Spectrum Disorder diagnosis (Sibs ASD) are at high risk for language delay (LD) as well as infants born preterm, especially those with an extremely low gestational age (ELGA, GA 64 28 weeks). Gestures play a crucial role in language development and delays in gesture production may have negative cascading effects on it. The present exploratory study examined gesture production in 18-month-old infants with different underlying risks for LD. Seventy monolingual United States infants (41 Sibs ASD with no eventual ASD diagnosis and 29 infants with a typically developing older sibling -Sibs TD) and 40 monolingual Italian infants (20 ELGA without major cerebral damages, congenital malformations or sensory impairments and 20 full-term - FT infants, GA 65 37 weeks) were included. Both groups were followed longitudinally from 18 to 24, 30, and 36 months (corrected for ELGA infants). A 30-minute mother-infant play session with age-appropriate toys was video recorded at 18 months of age. Deictic (requesting, pointing, showing and giving), conventional, and representational gestures spontaneously produced by infants were coded; rate per 10 min was calculated. LD was defined as a score 6410th percentile on the American English or Italian version of the MacArthur-Bates CDI on at least two time points between 18 and 36 months. Fifteen Sibs ASD and 9 ELGA infants were identified as infants with LD. Sibs ASD-LD and Sibs ASD-no LD produced fewer pointing gestures compared to Sibs TD (p = 0.038; p = 0.004); ELGA-LD infants produced significantly fewer pointing gestures than ELGA-no LD (p = 0.024) and FT (p = 0.006) infants. Low rates of pointing at 18 months are a marker of LD in Sibs ASD and ELGA infants. The potential implications of reduced pointing production and characteristics of different populations at risk for LD should be considered for understanding the emergence of LD

A Computational Framework for Pre-Interventional Planning of Peripheral Arteriovenous Malformations

PURPOSE: Peripheral arteriovenous malformations (pAVMs) are congenital lesions characterised by abnormal high-flow, low-resistance vascular connections-the so-called nidus-between arteries and veins. The mainstay treatment typically involves the embolisation of the nidus, however the complexity of pAVMs often leads to uncertain outcomes. This study aims at developing a simple, yet effective computational framework to aid the clinical decision making around the treatment of pAVMs using routinely acquired clinical data. METHODS: A computational model was developed to simulate the pre-, intra-, and post-intervention haemodynamics of a patient-specific pAVM. A porous medium of varying permeability was employed to simulate the sclerosant effect on the nidus haemodynamics. Results were compared against clinical data (digital subtraction angiography, DSA, images) and experimental flow-visualization results in a 3D-printed phantom of the same pAVM. RESULTS: The computational model allowed the simulation of the pAVM haemodynamics and the sclerotherapy-induced changes at different interventional stages. The predicted inlet flow rates closely matched the DSA-derived data, although the post-intervention one was overestimated, probably due to vascular system adaptations not accounted for numerically. The nidus embolization was successfully captured by varying the nidus permeability and increasing its hydraulic resistance from 0.330 to 3970 mmHg s ml-1. The nidus flow rate decreased from 71% of the inlet flow rate pre-intervention to 1%: the flow completely bypassed the nidus post-intervention confirming the success of the procedure. CONCLUSION: The study demonstrates that the haemodynamic effects of the embolisation procedure can be simulated from routinely acquired clinical data via a porous medium with varying permeability as evidenced by the good qualitative agreement between numerical predictions and both in vivo and in vitro data. It provides a fundamental building block towards a computational treatment-planning framework for AVM embolisation

Interference with the Cannabinoid Receptor CB1R Results in Miswiring of GnRH3 and AgRP1 Axons in Zebrafish Embryos

The G protein-coupled cannabinoid receptors type 1 (CB1R) and type 2 (CB2R), and their endocannabinoid (eCBs) ligands, have been implicated in several aspects of brain wiring during development. Here we aim to assess whether interfering with CB1R affects development, neuritogenesis and pathfinding of GnRH and AgRP neurons, forebrain neurons that control respectively reproduction and appetite. We pharmacologically and genetically interfered with CB1R in zebrafish strains with fluorescently labeled GnRH3 and the AgRP1 neurons. By applying CB1R antagonists we observed a reduced number of GnRH3 neurons, fiber misrouting and altered fasciculation. Similar phenotypes were observed by CB1R knockdown. Interfering with CB1R also resulted in a reduced number, misrouting and poor fasciculation of the AgRP1 neuron’s axonal projections. Using a bioinformatic approach followed by qPCR validation, we have attempted to link CB1R functions with known guidance and fasciculation proteins. The search identified stathmin-2, a protein controlling microtubule dynamics, previously demonstrated to be coexpressed with CB1R and now shown to be downregulated upon interference with CB1R in zebrafish. Together, these results raise the likely possibility that embryonic exposure to low doses of CB1R-interfering compounds could impact on the development of the neuroendocrine systems controlling sexual maturation, reproduction and food intake

Virtual TEVAR: Overcoming the Roadblocks of In-Silico Tools for Aortic Dissection Treatment

The use of in silico tools for the interventional planning of complex vascular conditions, such as Aortic Dissections has been often limited by high computational cost, involving long timescales for accurate results to be produced and low numbers of patients, precluding the use of statistical analyses to inform individual-level models. In the paper [Theranostics 2018; 8(20):5758-5771. doi:10.7150/thno.28944], Chen et al. proposed a novel algorithm to compute patient-specific ‘virtual TEVAR’ that will help clinicians to approach individual treatment and decision-making based on objective and quantifiable metrics and validated on a cohort of 66 patients in real time. This research will significantly impact the field and has the potential to transform the way clinical interventions will be approached in the futur

Adaptation and development of software simulation methodologies for cardiovascular engineering: present and future challenges from an end-user perspective

This paper describes the use of diverse software tools in cardiovascular applications. These tools were primarily developed in the field of engineering and the applications presented push the boundaries of the software to address events related to venous and arterial valve closure, exploration of dynamic boundary conditions or the inclusion of multi-scale boundary conditions from protein to organ levels. The future of cardiovascular research and the challenges that modellers and clinicians face from validation to clinical uptake are discussed from an end-user perspective