600 research outputs found
Faith and science dialogue in the Shroud of Turin
The science of the Shroud of Turin –or sindonology– began with the photograph
of this religious relic by Secondo Pia in 1898. In a cultural context where the
thesis of the constant conflict between religion and science is still alive, sindonology
stands out as a paradigm of the constructive dialogue between faith and science. Independent
from the issue of the authenticity of the relic, here is the reflection of such
dialogue displaying the mutual services that faith and science render one another.
Sindonology also stands out for being a paradigm of interdisciplinary study, which
demands the overcoming of knowledge fragmentation
Brain energetics plays a key role in the coordination of electrophysiology, metabolism and hemodynamics: evidence from an integrated computational model
The energetic needs of brain cells at rest and during elevated neuronal activation has been the topic of many investigations where mathematical models have played a significant role providing a context for the interpretation of experimental findings. A recently proposed mathematical model, comprising a double feedback between cellular metabolism and electrophysiology, sheds light on the interconnections between the electrophysiological details associated with changes in the frequency of neuronal firing and the corresponding metabolic activity. We propose a new extended mathematical model comprising a three-way feedback connecting metabolism, electrophysiology and hemodynamics. Upon specifying the time intervals of higher neuronal activation, the model generates a potassium based signal leading to the concomitant increase in cerebral blood flow with associated vasodilation and metabolic changes needed to sustain the increased energy demand. The predictions of the model are in good qualitative and quantitative agreement with experimental findings reported in the literature, even predicting a slow after-hyperpolarization of a duration of approximately 16 s matching experimental observations.The work of Daniela Calvetti was partly support by NSF grants DMS-1522334 and NIH grant 1U01 GM111251-01. The work of Erkki Somersalo was partly support by NSF grants DMS 1714617 and NIH grant 1U01GM111251-01
Spectral changes of brain activity in rat offspring exposed to aluminium during gestation and lactation
Exposure to aluminium during gestation causes changes in mammalian brain development and behavior. Our aim was to perform spectral analysis on electrocortical activity of Sprague Dawley male pups (30±3 days of age) whose mothers were treated with aluminium during gestation and lactation. There was a higher presence of power spectra in the delta range of parietal electrocortical activity, a lower presence in the theta range and increased values of the parameter DT as the ratio of delta to theta range in pups indirectly exposed to aluminium (whose mothers were drinking a 0.5% water solution of aluminium chloride during the gestation and lactation periods), compared to controls
The challenge of predicting groundwater quality impacts in a CO2 leakage scenario: Results from field, laboratory, and modeling studies at a natural analog site in New Mexico, USA
AbstractA vital aspect to public and regulatory acceptance of carbon sequestration is assurance that groundwater resources will be protected. Theoretical and laboratory studies can, to some extent, be used to predict the consequences of leakage. However, direct observations of CO2 flowing through shallow drinking water aquifers are invaluable for informing credible risk assessments. To this end, we have sampled shallow wells in a natural analog site in New Mexico, USA, where CO2 from natural sources is upwelling from depth. We collected major ion, trace element, and isotopic (3H, 18O, and Sr) data and, coupled with laboratory experiments and reactive transport modeling, have concluded that the major control on groundwater quality at this site is not chemical reaction of CO2 with the aquifer but intrusion of saline waters upwelling with the CO2.Using reactive transport modeling based on field data, we show the difference in reactivity of the CO2 and CO2/saline water source terms, particularly with respect to carbonate mineralogy. Sr isotopes were used to investigate whether aquifer waters were affected by carbonate mineral reaction with CO2 or by saline water intrusion. Preliminary data suggest that Sr isotopes can successfully be used to discriminate between the two types of source terms at Chimayó; this technique shows promise for monitoring CCS sites.In developing predictive capabilities for future sites, it is critical to identify the solid phases and specific reactions controlling dissolved trace metal concentrations in both the presence and absence of CO2. We have conducted laboratory experiments to identify these phases and have found that some elements (e.g., U, Ca) are largely controlled by ion exchange and/or carbonate minerals. In the experiments, the concentration of some metals increases after exposure to CO2 (although concentrations remain below the U.S. EPA primary drinking water standards); we are currently extending these experiments to determine if the reactions causing the increase are reversible and, if so, on what time scales. Metal scavenging by secondary mineral precipitation, as observed at other natural analog sites, may be important at certain temporal scales.We are using the information gained from this field and laboratory study to develop predictive models for application to risk assessment at future CCS sites. The models will be particularly useful in identifying the temporal and spatial scales of water quality changes and in developing possible mitigation strategies in the case of leaks at engineered CCS sites
Persistent Coxiella burnetii Infection in Mice Overexpressing IL-10: An Efficient Model for Chronic Q Fever Pathogenesis
Interleukin (IL)-10 increases host susceptibility to microorganisms and is involved in intracellular persistence of bacterial pathogens. IL-10 is associated with chronic Q fever, an infectious disease due to the intracellular bacterium Coxiella burnetii. Nevertheless, accurate animal models of chronic C. burnetii infection are lacking. Transgenic mice constitutively expressing IL-10 in macrophages were infected with C. burnetti by intraperitoneal and intratracheal routes and infection was analyzed through real-time PCR and antibody production. Transgenic mice exhibited sustained tissue infection and strong antibody response in contrast to wild-type mice; thus, bacterial persistence was IL-10-dependent as in chronic Q fever. The number of granulomas was low in spleen and liver of transgenic mice infected through the intraperitoneal route, as in patients with chronic Q fever. Macrophages from transgenic mice were unable to kill C. burnetii. C. burnetii–stimulated macrophages were characterized by non-microbicidal transcriptional program consisting of increased expression of arginase-1, mannose receptor, and Ym1/2, in contrast to wild-type macrophages in which expression of inducible NO synthase and inflammatory cytokines was increased. In vivo results emphasized macrophage data. In spleen and liver of transgenic mice infected with C. burnetii by the intraperitoneal route, the expression of arginase-1 was increased while microbicidal pathway consisting of IL-12p40, IL-23p19, and inducible NO synthase was depressed. The overexpression of IL-10 in macrophages prevents anti-infectious competence of host, including the ability to mount granulomatous response and microbicidal pathway in tissues. To our knowledge, this is the first efficient model for chronic Q fever pathogenesis
Building an Online Learning Community for Technology Integration in Education
Our professional learning community (PLC), or the Technology Integration Learning Community (TILC), consists of nine professors from the Fischler College of Education at Nova Southeastern University who embody a wide range of knowledge and skills related to instruction, research, and technology. Our TILC provides a supportive, collaborative, safe, and non-judgmental environment for sharing that knowledge (and questions) about technology tools and ideas that can be used to enhance both instruction and learning. Through a self-study, the TILC developed a framework for members to improve their own effectiveness when working with students enrolled in their courses at both the graduate and undergraduate levels
A histidine-rich metal binding domain at the N terminus of Cu,Zn-superoxide dismutases from pathogenic bacteria: a novel strategy for metal chaperoning.
A group of Cu,Zn-superoxide dismutases from pathogenic bacteria is characterized by histidine-rich N-terminal extensions that are in a highly exposed and mobile conformation. This feature allows these proteins to be readily purified in a single step by immobilized metal affinity chromatography. The Cu,Zn-superoxide dismutases from both Haemophilus ducreyi and Haemophilus parainfluenzae display anomalous absorption spectra in the visible region due to copper binding at the N-terminal region. Reconstitution experiments of copper-free enzymes demonstrate that, under conditions of limited copper availability, this metal ion is initially bound at the N-terminal region and subsequently transferred to an active site. Evidence is provided for intermolecular pathways of copper transfer from the N-terminal domain of an enzyme subunit to an active site located on a distinct dimeric molecule. Incubation with EDTA rapidly removes copper bound at the N terminus but is much less effective on the copper ion bound at the active site. This indicates that metal binding by the N-terminal histidines is kinetically favored, but the catalytic site binds copper with higher affinity. We suggest that the histidine-rich N-terminal region constitutes a metal binding domain involved in metal uptake under conditions of metal starvation in vivo. Particular biological importance for this domain is inferred by the observation that its presence enhances the protection offered by periplasmic Cu,Zn-superoxide dismutase toward phagocytic killing
Oxygen-deficient water zones in the Baltic Sea promote uncharacterized Hg methylating microorganisms in underlying sediments
Human-induced expansion of oxygen-deficient zones can have dramatic impacts on marine systems and its resident biota. One example is the formation of the potent neurotoxic methylmercury (MeHg) that is mediated by microbial methylation of inorganic divalent Hg (Hg-II) under oxygen-deficient conditions. A negative consequence of the expansion of oxygen-deficient zones could be an increase in MeHg production due to shifts in microbial communities in favor of microorganisms methylating Hg. There is, however, limited knowledge about Hg-methylating microbes, i.e., those carrying hgc genes critical for mediating the process, from marine sediments. Here, we aim to study the presence of hgc genes and transcripts in metagenomes and metatranscriptomes from four surface sediments with contrasting concentrations of oxygen and sulfide in the Baltic Sea. We show that potential Hg methylators differed among sediments depending on redox conditions. Sediments with an oxygenated surface featured hgc-like genes and transcripts predominantly associated with uncultured Desulfobacterota (OalgD group) and Desulfobacterales (including Desulfobacula sp.) while sediments with a hypoxic-anoxic surface included hgc-carrying Verrucomicrobia, unclassified Desulfobacterales, Desulfatiglandales, and uncharacterized microbes. Our data suggest that the expansion of oxygen-deficient zones in marine systems may lead to a compositional change of Hg-methylating microbial groups in the sediments, where Hg methylators whose metabolism and biology have not yet been characterized will be promoted and expand
Thermal alterations in patients with inflammatory diseases: a comparison between psoriatic and rheumatoid arthritis
Functional infrared imaging (fIRI) is used to provide information on circulation, thermal properties and thermoregulatory function of the cutaneous tissue in several clinical settings. This study aims to evaluate the application of fIRI in rheumatoid arthritis (RA) assessment, evaluating the thermoregulatory alterations due to joint inflammation in RA patients both in basal conditions and after a mild functional (isometric) exercise, using the same protocol we projected in our recent work on psoriatic arthritis (PsA); fIRI outcomes were compared with those provided by power-Doppler ultrasonography. Ten patients with RA and 11 healthy controls were enrolled in the study. The cutaneous temperature dynamics of 20 regions of interest located on the dominant hand were recorded by means of high-resolution thermal imaging at baseline and after a functional exercise. RA patients showed lower thermal parameters compared to healthy controls, suggesting that the RA-related inflammatory state alters the normal thermal properties of the skin overlying inflamed joints. These results are different from PsA data observed in the previous study. fIRI applied to the study of the response to a functional stimulus may represent an innovative, non-invasive, and operator-independent method for the assessment of early R
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