Top-Down Causation by Information Control: From a Philosophical Problem to a Scientific Research Program

It has been claimed that different types of causes must be considered in biological systems, including top-down as well as same-level and bottom-up causation, thus enabling the top levels to be causally efficacious in their own right. To clarify this issue, important distinctions between information and signs are introduced here and the concepts of information control and functional equivalence classes in those systems are rigorously defined and used to characterise when top down causation by feedback control happens, in a way that is testable. The causally significant elements we consider are equivalence classes of lower level processes, realised in biological systems through different operations having the same outcome within the context of information control and networks.Comment: Revised version to meet referee's comments, and responding to a paper by Wegscheid et al that was not mentioned in the previous version. 23 pages, 9 figure

Visualizing the Quantum Interaction Picture in Phase Space

We illustrate the correspondence between the quantum Interaction Picture-evolution of the state of a quantum system in Hilbert space and a combination of local and global transformations of its Wigner function in phase space. To this aim, we consider the time-evolution of a quantized harmonic oscillator driven by both a linear and a quadratic (in terms of bosonic creation and annihilation operators) potentials and employ the Magnus series to derive the exact form of the time-evolution operator. In this case, the Interaction Picture corresponds to a local transformation of phase space-reference frame into the one that is co-moving with the Wigner function.Comment: Submitted to New Journal of Physic

Price Competition, Fluctuations, and Welfare Guarantees

In various markets where sellers compete in price, price oscillations are observed rather than convergence to equilibrium. Such fluctuations have been empirically observed in the retail market for gasoline, in airline pricing and in the online sale of consumer goods. Motivated by this, we study a model of price competition in which an equilibrium rarely exists. We seek to analyze the welfare, despite the nonexistence of an equilibrium, and present welfare guarantees as a function of the market power of the sellers. We first study best response dynamics in markets with sellers that provide a homogeneous good, and show that except for a modest number of initial rounds, the welfare is guaranteed to be high. We consider two variations: in the first the sellers have full information about the valuation of the buyer. Here we show that if there are $n$ items available across all sellers and $n_{\max}$ is the maximum number of items controlled by any given seller, the ratio of the optimal welfare to the achieved welfare will be at most $\log(\frac{n}{n-n_{\max}+1})+1$. As the market power of the largest seller diminishes, the welfare becomes closer to optimal. In the second variation we consider an extended model where sellers have uncertainty about the buyer's valuation. Here we similarly show that the welfare improves as the market power of the largest seller decreases, yet with a worse ratio of $\frac{n}{n-n_{\max}+1}$. The exponential gap in welfare between the two variations quantifies the value of accurately learning the buyer valuation. Finally, we show that extending our results to heterogeneous goods in general is not possible. Even for the simple class of $k$-additive valuations, there exists a setting where the welfare approximates the optimal welfare within any non-zero factor only for $O(1/s)$ fraction of the time, where $s$ is the number of sellers

Ultrasonographic assessment of normal jugular veins in Standardbred horses

Ultrasonography (US) is the recommended imaging technique to evaluate jugular veins. This prospective randomized clinical study was designed to collect a series of B-mode US measurements of manually distended jugular veins in healthy Italian Standardbreds and to find possible correlations between ultrasound measurements and animal morphometric characteristics. Forty-two horses, eight males and 34 females (range 3-22\u2009years; bodyweight 494.4\u2009\ub1\u200941.7\u2009kg), were included in the study. The diameters and wall thicknesses of both jugular veins were measured at three different sites of the neck. The differences in ultrasound measurements based on scans, age, gender, side, and site of the neck were evaluated by ANOVA or by the Kruskal-Wallis test. The effects of the morphometric measures on each ultrasound parameter were evaluated by MANOVA (P\u2009<\u20090.05)

Ultrasonographic assessment of normal jugular veins in Standardbred horses

Ultrasonography (US) is the recommended imaging technique to evaluate jugular veins. This prospective randomized clinical study was designed to collect a series of B-mode US measurements of manually distended jugular veins in healthy Italian Standardbreds and to find possible correlations between ultrasound measurements and animal morphometric characteristics. Forty-two horses, eight males and 34 females (range 3-22 years; bodyweight 494.4 ± 41.7 kg), were included in the study. The diameters and wall thicknesses of both jugular veins were measured at three different sites of the neck. The differences in ultrasound measurements based on scans, age, gender, side, and site of the neck were evaluated by ANOVA or by the Kruskal-Wallis test. The effects of the morphometric measures on each ultrasound parameter were evaluated by MANOVA (P < 0.05)

The use of platelet-rich plasma for treatment of tenodesmic lesions in horses: A systematic review and meta-analysis of clinical and experimental data

The use of platelet-rich plasma (PRP) to enhance tenodesmic lesion healing has been questioned over the years. The aim of this study was to evaluate current literature to establish the effectiveness of PRP for treating tenodesmic lesions through a systematic review, in accordance with the PRISMA guidelines, and a meta-analysis. Studies comparing PRP with placebo or other treatments for horses with tenodesmic injuries or evaluated PRP effect on tendon and ligament explants were included. Outcomes were clinical, ultrasound, histologic, molecular evaluation, and adverse effects. Two authors independently extracted data and assessed each study’s risk of bias. Treatment effects were evaluated using risk ratios for dichotomous data, together with 95% CI. Data were pooled using the random-effects model. The quality of the evidence for each outcome was assessed using GRADE criteria. Twenty-four trials met inclusion criteria for systematic review, while fifteen studies were included in the meta-analysis. Results showed no significant differences in the outcomes between PRP and control groups. Finally, there is no definitive evidence that PRP enhances tendons and ligaments healing. Therefore, there is a need for more controlled trials to draw a firmer conclusion about the efficacy of PRP as a treatment for tenodesmic lesions in the horse

Inhibition of Bone Marrow-Derived Mesenchymal Stem Cells Homing Towards Triple-Negative Breast Cancer Microenvironment Using an Anti-PDGFRβ Aptamer

Bone marrow-derived mesenchymal stem cells (BM-MSCs) are shown to participate in tumor progression by establishing a favorable tumor microenvironment (TME) that promote metastasis through a cytokine networks. However, the mechanism of homing and recruitment of BM-MSCs into tumors and their potential role in malignant tissue progression is poorly understood and controversial. Here we show that BM-MSCs increase aggressiveness of triple-negative breast cancer (TNBC) cell lines evaluated as capability to migrate, invade and acquire stemness markers. Importantly, we demonstrate that the treatment of BM-MSCs with a nuclease-resistant RNA aptamer against platelet-derived growth factor receptor β (PDGFRβ) causes the inhibition of receptor-dependent signaling pathways thus drastically hampering BM-MSC recruitment towards TNBC cell lines and BM-MSCs trans-differentiation into carcinoma-associated fibroblast (CAF)-like cells. Moreover, in vivo molecular imaging analysis demonstrated the aptamer ability to prevent BM-MSCs homing to TNBC xenografts. Collectively, our results indicate the anti-PDGFRβ aptamer as a novel therapeutic tool to interfere with BM-MSCs attraction to TNBC providing the rationale to further explore the aptamer in more complex pre-clinical settings

A first experimental test of de Broglie-Bohm theory against standard quantum mechanics

De Broglie - Bohm (dBB) theory is a deterministic theory, built for reproducing almost all Quantum Mechanics (QM) predictions, where position plays the role of a hidden variable. It was recently shown that different coincidence patterns are predicted by QM and dBB when a double slit experiment is realised under specific conditions and, therefore, an experiment can test the two theories. In this letter we present the first realisation of such a double slit experiment by using correlated photons produced in type I Parametric Down Conversion. Our results confirm QM contradicting dBB predictions

Pre-existing invasive fungal infection is not a contraindication for allogeneic HSCT for patients with hematologic malignancies: a CIBMTR study.

Patients with prior invasive fungal infection (IFI) increasingly proceed to allogeneic hematopoietic cell transplantation (HSCT). However, little is known about the impact of prior IFI on survival. Patients with pre-transplant IFI (cases; n=825) were compared with controls (n=10247). A subset analysis assessed outcomes in leukemia patients pre- and post 2001. Cases were older with lower performance status (KPS), more advanced disease, higher likelihood of AML and having received cord blood, reduced intensity conditioning, mold-active fungal prophylaxis and more recently transplanted. Aspergillus spp. and Candida spp. were the most commonly identified pathogens. 68% of patients had primarily pulmonary involvement. Univariate and multivariable analysis demonstrated inferior PFS and overall survival (OS) for cases. At 2 years, cases had higher mortality and shorter PFS with significant increases in non-relapse mortality (NRM) but no difference in relapse. One year probability of post-HSCT IFI was 24% (cases) and 17% (control, P&lt;0.001). The predominant cause of death was underlying malignancy; infectious death was higher in cases (13% vs 9%). In the subset analysis, patients transplanted before 2001 had increased NRM with inferior OS and PFS compared with later cases. Pre-transplant IFI is associated with lower PFS and OS after allogeneic HSCT but significant survivorship was observed. Consequently, pre-transplant IFI should not be a contraindication to allogeneic HSCT in otherwise suitable candidates. Documented pre-transplant IFI is associated with lower PFS and OS after allogeneic HSCT. However, mortality post transplant is more influenced by advanced disease status than previous IFI. Pre-transplant IFI does not appear to be a contraindication to allogeneic HSCT