Modeling multi-sensory feedback control of zebrafish in a flow

Understanding how animals navigate complex environments is a fundamental challenge in biology and a source of inspiration for the design of autonomous systems in engineering. Animal orientation and navigation is a complex process that integrates multiple senses, whose function and contribution are yet to be fully clarified. Here, we propose a data-driven mathematical model of adult zebrafish engaging in counter-flow swimming, an innate behavior known as rheotaxis. Zebrafish locomotion in a two-dimensional fluid flow is described within the finite-dipole model, which consists of a pair of vortices separated by a constant distance. The strength of these vortices is adjusted in real time by the fish to afford orientation and navigation control, in response to of the multi-sensory input from vision, lateral line, and touch. Model parameters for the resulting stochastic differential equations are calibrated through a series of experiments, in which zebrafish swam in a water channel under different illumination conditions. The accuracy of the model is validated through the study of a series of measures of rheotactic behavior, contrasting results of real and in-silico experiments. Our results point at a critical role of hydromechanical feedback during rheotaxis, in the form of a gradient-following strategy.     

'Click' synthesis of a triazole-based inhibitor of Met functions in cancer cells

The use of Cu(I)-catalyzed azide-alkyne 1,3-dipolar cycloaddition permitted the synthesis of a new compound that is able to inhibit the HGF-induced scattering of MDCK (epithelial cells) and in vitro tumorigenesis of H1437 (non-small-cell lung cancer) and GTL-16 (human gastric carcinoma). In agreement with biochemical and biological results, docking studies within the ATP binding site of Met suggested for the new synthesized compound a binding mode similar to that of the active compound Triflorcas previously reported.     

Crystal structure of Plasmodium falciparum thioredoxin reductase, a validated drug target

Plasmodium falciparum is the vector of the most prevalent and deadly form of malaria, and, among the Plasmodium species, it is the one with the highest rate of drug resistance. At the basis of a rational drug design project there is the selection and characterization of suitable target(s). Thioredoxin reductase, the first protection against reactive oxygen species in the erythrocytic phase of the parasite, is essential for its survival. Hence it represents a good target for the design of new anti-malarial active compounds. In this paper we present the first crystal structure of recombinant P. falciparum thioredoxin reductase (PfTrxR) at 2.9 Å and discuss its differences with respect to the human orthologue. The most important one resides in the dimer interface, which offers a good binding site for selective non competitive inhibitors. The striking conservation of this feature among the Plasmodium parasites, but not among other Apicomplexa parasites neither in mammals, boosts its exploitability.     

Beverage specific alcohol intake in a population-based study: Evidence for a positive association between pulmonary function and wine intake

Background  

Lung function is a strong predictor of cardiovascular and all-cause mortality. Previous studies suggest that alcohol exposure may be linked to impaired pulmonary function through oxidant-antioxidant mechanisms. Alcohol may be an important source of oxidants; however, wine contains several antioxidants. In this study we analyzed the relation of beverage specific alcohol intake with forced expiratory volume in one second (FEV₁) and forced vital capacity (FVC) in a random sample of 1555 residents of Western New York, USA.     

Light as an information carrier underwater

Light is a source of both energy and information for the biota.The spatial, temporal and spectral variability of light experiencedby marine phytoplankton differs significantly from that experiencedby terrestrial plants, due to the selective attenuation of solarirradiance in the aquatic medium. In the present study we analysedsuch variability and focused, in particular, on those bandswithin the spectrum that may act as potential signals for physiologicalresponses. Our results demonstrate that the spectral variationof the light field carries information on the time of day, thevertical position and the presence of very close neighbours,also underwater. This is consistent with the recent findingsof a widespread occurrence of photoreceptors in marine algae.We show also that red photoreceptors, whose presence in marinealgae was difficult to reconcile with the strong attenuationof long wavelengths by water, may be triggered at depth by thered light generated by transpectral processes.     

Role of DAMPs and of Leukocytes Infiltration in Ischemic Stroke: Insights from Animal Models and Translation to the Human Disease

Stroke is a leading cause of death and disability worldwide. Several mechanisms are involved in the pathogenesis of ischemic stroke (IS). The contributory role of the inflammatory and immunity processes was demonstrated both in vitro and in animal models, and was confirmed in humans. IS evokes an immediate inflammatory response that involves complex cellular and molecular mechanisms. All components of the innate and adaptive immunity systems are involved in several steps of the ischemic cascade. In the early phase, inflammatory and immune mechanisms contribute to the brain tissue damage, whereas, in the late phase, they participate to the tissue repair processes. In particular, damage-associated molecular patterns (DAMPs) appear critical for the promotion of altered blood brain barrier permeability, leukocytes infiltration, tissue edema and brain injury. Conversely, the activation of regulatory T lymphocytes (Tregs) plays protective effects. The identification of specific cellular/molecular elements belonging to the inflammatory and immune responses, contributing to the brain ischemic injury and tissue remodeling, offers the advantage to design adequate therapeutic strategies. In this article, we will present an overview of the knowledge on inflammatory and immunity processes in IS, with a particular focus on the role of DAMPs and leukocytes infiltration. We will discuss evidence obtained in preclinical models of IS and in humans. The main molecular mechanisms useful for the development of novel therapeutic approaches will be highlighted. The translation of experimental findings to the human disease is still a difficult step to pursue. Further investigations are required to fill up the existing gaps.

     

Decomposition of woody debris in Mediterranean ecosystems: the role of wood chemical and anatomical traits

Plant and Soil - Data about woody debris (WD) decomposition are very scarce for the Mediterranean basin. The specific aim of this work is to explore the relationships between WD traits with the...