Forced quasi-periodic oscillations in strongly dissipative systems of any finite dimension

We consider a class of singular ordinary differential equations describing analytic systems of arbitrary finite dimension, subject to a quasi-periodic forcing term and in the presence of dissipation. We study the existence of response solutions, i.e. quasi-periodic solutions with the same frequency vector as the forcing term, in the case of large dissipation. We assume the system to be conservative in the absence dissipation, so that the forcing term is --- up to the sign --- the gradient of a potential energy, and both the mass and damping matrices to be symmetric and positive definite. Further, we assume a non-degeneracy condition on the forcing term, essentially that the time-average of the potential energy has a strict local minimum. On the contrary, no condition is assumed on the forcing frequency; in particular we do not require any Diophantine condition. We prove that, under the assumptions above, a response solution always exist provided the dissipation is strong enough. This extends results previously available in literature in the one-dimensional case.Comment: 20 pages. arXiv admin note: substantial text overlap with arXiv:1606.0687

The Circadian Clock, the Immune System, and Viral Infections: The Intricate Relationship Between Biological Time and Host-Virus Interaction

Living beings spend their lives and carry out their daily activities interacting with environmental situations that present space-time variations and that involve contact with other life forms, which may behave as commensals or as invaders and/or parasites. The characteristics of the environment, as well as the processes that support the maintenance of life and that characterize the execution of activities of daily life generally present periodic variations, which are mostly synchronized with the light-dark cycle determined by Earth's rotation on its axis. These rhythms with 24-h periodicity, defined as circadian, influence events linked to the interaction between hosts and hosted microorganisms and can dramatically determine the outcome of this interplay. As for the various pathological conditions resulting from host-microorganism interactions, a particularly interesting scenario concerns infections by viruses. When a viral agent enters the body, it alters the biological processes of the infected cells in order to favour its replication and to spread to various tissues. Though our knowledge concerning the mutual influence between the biological clock and viruses is still limited, recent studies start to unravel interesting aspects of the clock-virus molecular interplay. Three different aspects of this interplay are addressed in this mini-review and include the circadian regulation of both innate and adaptive immune systems, the impact of the biological clock on viral infection itself, and finally the putative perturbations that the virus may confer to the clock leading to its deregulation

A new competetive advantage over the cloud

CEM

Alteration of Hypothalamic–Pituitary–Thyroid Axis Function in Non-Small-Cell Lung Cancer Patients

The aim of this study was to evaluate the hypothalamic–pituitary–thyroid (HPT) axis function in patients suffering from lung cancer. Thyrotropin-releasing hormone (TRH), thyroid-stimulating hormone (TSH), free thyroxine (FT4), interleukin (IL)-2, and melatonin serum levels were measured in blood samples collected every 4 hours for 24 hours from 11 healthy participants (H; ages 35-53 years) and 9 patients suffering from non-small-cell lung cancer (C; ages 43-63 years). Relationships between hormone levels overall and over time of day were evaluated within and among groups. A prominent circadian rhythm with peaks near midnight was present for TSH and melatonin serum levels in both H and C, indicating similar synchronization of the main body clock to the 24-hour environmental light–dark cycle. As regards 24-hour means in H and C, TSH was lower in C, whereas TRH, FT4, and IL-2 were higher in C, with no difference in melatonin levels. Simple linear regression, FT4 versus TRH, showed a positive correlation in H..

Environmental Valorization of Rice Waste as Adsorbent Material for the Removal of Nitrates from Water

An innovative water-treatment process consisting in reducing the nitrate concentration by using an active silica filter obtained from ashes produced during rice-straw thermal treatment has been developed by the LIFE LIBERNITRATE project. A life-cycle assessment (LCA) was carried out to evaluate the environmental impacts of this innovative process, from the production of ashes and extraction and activation of silica to the water treatment. These results were compared to the environmental impact derived from the use of bottled water, instead of tap water, where traditional water treatments (i.e., reverse osmosis) may not be available due to the high installation and operating costs. The comparison showed that the proposed innovative process could contribute to reducing the environmental impact in almost all analyzed impact categories (from 20% for photochemical oxidation to 90% for abiotic depletion) with respect to the use of bottled water. In addition, if conveniently optimized (for example reducing the amount of active silica used per day), the innovative process could further reduce the ecological footprint and be more eco-friendly than the use of bottled water and could be applied to treating water in small towns where reverse osmosis may not be installed. The LCA proved that the innovative process could contribute to reducing the environmental impact of water-treatment technologies resulting in lower environmental indicators with respect to the use of bottled water

Analysis and Comparison of Equations-of-State with p-ρ-T Experimental Data for CO2 and CO2-Mixture Pipeline Transport

Abstract Transport is an important feature of the CCS process as the CO2 quality requested by pipelines may influence the choice of the capture technology and its limit performance requirements. So, the knowledge of the thermodynamic properties of CO2-mixtures has an important role, however a suitable equation of state under the appropriate conditions for pipeline transport has not been clearly defined yet. In this paper different equations of state for predicting densities of CO2 and CO2 mixtures have been analyzed and compared with experimental data found in literature or obtained by authors performing specific laboratory p-ρ-T measurements

Altered time structure of neuro-endocrine-immune system function in lung cancer patients

<p>Abstract</p> <p>Background</p> <p>The onset and the development of neoplastic disease may be influenced by many physiological, biological and immunological factors. The nervous, endocrine and immune system might act as an integrated unit to mantain body defense against this pathological process and reciprocal influences have been evidenced among hypothalamus, pituitary, thyroid, adrenal, pineal gland and immune system. In this study we evaluated differences among healthy subjects and subjects suffering from lung cancer in the 24-hour secretory profile of melatonin, cortisol, TRH, TSH, FT4, GH, IGF-1 and IL-2 and circadian variations of lymphocyte subpopulations. </p> <p>Methods</p> <p>In ten healthy male volunteers (age range 45-66) and ten male patients with untreated non small cell lung cancer (age range 46-65) we measured melatonin, cortisol, TRH, TSH, FT4, GH, IGF-1 and IL-2 serum levels and percentages of lymphocyte subpopulations on blood samples collected every four hours for 24 hours. One-way ANOVA between the timepoints for each variable and each group was performed to look for a time-effect, the presence of circadian rhythmicity was evaluated, MESOR, amplitude and acrophase values, mean diurnal levels and mean nocturnal levels were compared.</p> <p>Results</p> <p>A clear circadian rhythm was validated in the control group for hormone serum level and for lymphocyte subsets variation. Melatonin, TRH, TSH, GH, CD3, CD4, HLA-DR, CD20 and CD25 expressing cells presented circadian rhythmicity with acrophase during the night. Cortisol, CD8, CD8^bright, CD8^dim, CD16, TcRδ1 and δTcS1 presented circadian rhythmicity with acrophase in the morning/at noon. FT4, IGF-1 and IL-2 variation did not show circadian rhythmicity. In lung cancer patients cortisol, TRH, TSH and GH serum level and all the lymphocyte subsubsets variation (except for CD4) showed loss of circadian rhythmicity. MESOR of cortisol, TRH, GH, IL-2 and CD16 was increased, whereas MESOR of TSH, IGF-1, CD8, CD8^bright, TcRδ1 and δTcS1 was decreased in cancer patients. The melatonin/cortisol mean nocturnal level ratio was decreased in cancer patients.</p> <p>Conclusion</p> <p>The altered secretion and loss of circadian rhythmicity of many studied factors observed in the subjects suffering from neoplastic disease may be expression of gradual alteration of the integrated function of the neuro-immune-endocrine system</p

Molecular dynamics recipes for genome research

Molecular dynamics (MD) simulation allows one to predict the time evolution of a system of interacting particles. It is widely used in physics, chemistry and biology to address specific questions about the structural properties and dynamical mechanisms of model systems. MD earned a great success in genome research, as it proved to be beneficial in sorting pathogenic from neutral genomic mutations. Considering their computational requirements, simulations are commonly performed on HPC computing devices, which are generally expensive and hard to administer. However, variables like the software tool used for modeling and simulation or the size of the molecule under investigation might make one hardware type or configuration more advantageous than another or even make the commodity hardware definitely suitable for MD studies. This work aims to shed lights on this aspect