240 research outputs found

    The Euclid Space Mission: development of end-to-end simulator software tools aimed at improving the wavelength calibration of NISP instrument spectroscopic data

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    This PhD thesis deals with the realization of two original software tools for the Euclid Space Mission: 1. an End-to-End Mission Performance Simulator (E2ES) 2. a code to improve the wavelength calibration of the Euclid NISP spectroscopic data. Euclid is a mission selected by the European Space Agency (ESA) at the end of 2011 to understand the nature of the dark Universe. Starting from 2022, Euclid will investigate the distance-redshift relationship and the evolution of cosmic structures by means of two instruments: the Visual Imager (VIS) and the Near-Infrared Spectrometer and Photometer (NISP). The NISP instrument is designed to carry out slitless spectroscopy (for galaxy clustering probe) and imaging photometry (to detect weak lensing effects) in the near-infrared (NIR) wavelength. The design of a space mission is a long and complex process. The support of dedicated software tools is necessary, especially for the performance analysis of the mission itself. The request is then for specific tools that can simulate the complete behavior of the probe, its payload (i.e. those elements of the spacecraft specifically dedicated to producing mission data), and scientific data acquisition starting from synthetic scenes. A mission performance simulator (E2ES) with reduced simulation capabilities (called "Proto E2ES") has been implemented using the Python programming language in the framework of the European Space Agency (ESA) contract IPL-PTE/GLC/al/241.2014. My research job focused on the verification and validation of the simulator. In accordance to actual ESA software standardization, I developed a verification and validation process (contained in the "Euclid E2ES Verification and Validation Plan") to check the consistency and meaningfulness of output data resulting from the entire simulation chain; to check that the simulation output products are within the identified figure of merit; to determine whether or not the simulator software complies with the scientific requirements established in the baseline requirements document, and to define the test cases for the verification. A simulation on the entire input test catalog has been performed and all test cases foreseen by the plan completed with success. Exploiting the experience matured on the validation of the Euclid proto-E2ES, a collaboration started with INAF-IASF Milano to assess if the wavelength calibration accuracy of the NISP spectroscopic data can be validated using spectra of bright stars. Using stellar spectra of the NASA InfraRed Telescope Facility (IRTF), a deformation is applied to the spectra itself in order to reproduce the non-ideal nature of the NISP instrument. Also reference stellar spectra ("templates")are deformed, and the best match between the observed deformed spectrum and template is obtained through the evaluation of a merit function, the correlation function. The correlation has then been computed for all stellar spectra of the input catalog and templates. The scatter of the cross-correlation peak position for the different magnitude bins has been plotted against the magnitude itself. Results show that NISP spectra location validation can be successfully performed using stellar spectra for stars up to J-band magnitude equal to 17.0. Furthermore, the spatially varying wavelength solution across the field-of-view is accurate to a level of 0.4 pixels for stellar spectra up to J-band magnitude = 15.5

    Nonprofit foundations spur translational research

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    Every year, hundreds of promising basic discoveries in the pharmacological field are lost and will never have a chance to be exploited for patients due to difficulties in clinical translation. This is especially true for most neurodegenerative disorders lacking disease-modifying therapies. Here we present the current scenario and our vision of a 'collective-impact' multistakeholder approach to expedite the development of new drugs

    Permissive role for mGlu1 metabotropic glutamate receptors in excitotoxic retinal degeneration

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    Neuroprotection is an unmet need in eye disorders characterized by retinal ganglion cell (RGC) death, such as prematurity-induced retinal degeneration, glaucoma, and age-related macular degeneration. In all these disorders excitotoxicity is a prominent component of neuronal damage, but clinical data discourage the development of NMDA receptor antagonists as neuroprotectants. Here, we show that activation of mGlu1 metabotropic glutamate receptors largely contributes to excitotoxic degeneration of RGCs. Mice at postnatal day 9 were challenged with a toxic dose of monosodium glutamate (MSG, 3g/kg), which caused the death of >70% of Brn-3a+ RGCs. Systemic administration of the mGlu1 receptor negative allosteric modulator (NAM), JNJ16259685 (2.5mg/kg, s.c.), was largely protective against MSG-induced RGC death. This treatment did not cause changes in motor behavior in the pups. We also injected MSG to crv4 mice, which lack mGlu1 receptors because of a recessive mutation of the gene encoding the mGlu1 receptor. MSG did not cause retinal degeneration in crv4 mice, whereas it retained its toxic activity in their wild-type littermates. These findings demonstrate that mGlu1 receptors play a key role in excitotoxic degeneration of RGCs, and encourage the study of mGlu1 receptor NAMs in models of retinal neurodegeneration

    Steps towards collective sustainability in biomedical research

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    The optimism surrounding multistakeholder research initiatives does not match the clear view of policies that are needed to exploit the potential of these collaborations. Here we propose some action items that stem from the integration between research advancements with the perspectives of patient-advocacy organizations, academia, and industry

    Report on the Pre- and Post-Cryogenic Warm Functional Test

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    This document presents the analysis of the two Warm Functional Tests (WFT) performed in the Centre Spatial du Li´ege before and after the cryogenic test campaign held in summer 2008. The procedure followed during the WFT is reported in [RD1]. Refer also to [AD1] for finer detail

    Nanotechnology Addressing Cutaneous Melanoma: The Italian Landscape

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    Cutaneous melanoma is one of the most aggressive solid tumors, with a low survival for the metastatic stage. Currently, clinical melanoma treatments include surgery, chemotherapy, targeted therapy, immunotherapy and radiotherapy. Of note, innovative therapeutic regimens concern the administration of multitarget drugs in tandem, in order to improve therapeutic efficacy. However, also, if this drug combination is clinically relevant, the patient’s response is not yet optimal. In this scenario, nanotechnology-based delivery systems can play a crucial role in the clinical treatment of advanced melanoma. In fact, their nano-features enable targeted drug delivery at a cellular level by overcoming biological barriers. Various nanomedicines have been proposed for the treatment of cutaneous melanoma, and a relevant number of them are undergoing clinical trials. In Italy, researchers are focusing on the pharmaceutical development of nanoformulations for malignant melanoma therapy. The present review reports an overview of the main melanoma-addressed nanomedicines currently under study in Italy, alongside the state of the art of melanoma therapy. Moreover, the latest Italian advances concerning the pre-clinical evaluation of nanomedicines for melanoma are described

    Catalase Takes Part in Rat Liver Mitochondria Oxidative Stress Defense

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    Highly purified rat liver mitochondria (RLM) when exposed to tert-butylhydroperoxide undergo matrix swelling, membrane potential collapse, and oxidation of glutathione and pyridine nucleotides, all events attributable to the induction of mitochondrial permeability transition. Instead, RLM, if treated with the same or higher amounts of H2O2 or tyramine, are insensitive or only partially sensitive, respectively, to mitochondrial permeability transition. In addition, the block of respiration by antimycin A added to RLM respiring in state 4 conditions, or the addition of H2O2, results in O2 generation, which is blocked by the catalase inhibitors aminotriazole or KCN. In this regard, H2O2 decomposition yields molecular oxygen in a 2:1 stoichiometry, consistent with a catalytic mechanism with a rate constant of 0.0346 s(-1). The rate of H2O2 consumption is not influenced by respiratory substrates, succinate or glutamate-malate, nor by N-ethylmaleimide, suggesting that cytochrome c oxidase and the glutathione-glutathione peroxidase system are not significantly involved in this process. Instead, H2O2 consumption is considerably inhibited by KCN or aminotriazole, indicating activity by a hemoprotein. All these observations are compatible with the presence of endogenous heme-containing catalase with an activity of 825 +/- 15 units, which contributes to mitochondrial protection against endogenous or exogenous H2O2. Mitochondrial catalase in liver most probably represents regulatory control of bioenergetic metabolism, but it may also be proposed for new therapeutic strategies against liver diseases. The constitutive presence of catalase inside mitochondria is demonstrated by several methodological approaches as follows: biochemical fractionating, proteinase K sensitivity, and immunogold electron microscopy on isolated RLM and whole rat liver tissue

    Upper limb motor rehabilitation impacts white matter microstructure in multiple sclerosis

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    Upper limb impairments can occur in patients with multiple sclerosis, affecting daily living activities; however there is at present no definite agreement on the best rehabilitation treatment strategy to pursue. Moreover, motor training has been shown to induce changes in white matter architecture in healthy subjects.This study aimed at evaluating the motor behavioral and white matter microstructural changes following a 2-month upper limb motor rehabilitation treatment based on task-oriented exercises in patients with multiple sclerosis.Thirty patients (18 females and 12 males; age. = 43.3. ±. 8.7. years) in a stable phase of the disease presenting with mild or moderate upper limb sensorimotor deficits were randomized into two groups of 15 patients each. Both groups underwent twenty 1-hour treatment sessions, three times a week. The "treatment group" received an active motor rehabilitation treatment, based on voluntary exercises including task-oriented exercises, while the "control group" underwent passive mobilization of the shoulder, elbow, wrist and fingers.Before and after the rehabilitation protocols, motor performance was evaluated in all patients with standard tests. Additionally, finger motor performance accuracy was assessed by an engineered glove.In the same sessions, every patient underwent diffusion tensor imaging to obtain parametric maps of fractional anisotropy, mean diffusivity, axial diffusivity, and radial diffusivity. The mean value of each parameter was separately calculated within regions of interest including the fiber bundles connecting brain areas involved in voluntary movement control: the corpus callosum, the corticospinal tracts and the superior longitudinal fasciculi.The two rehabilitation protocols induced similar effects on unimanual motor performance, but the bimanual coordination task revealed that the residual coordination abilities were maintained in the treated patients while they significantly worsened in the control group (p. = 0.002). Further, in the treatment group white matter integrity in the corpus callosum and corticospinal tracts was preserved while a microstructural integrity worsening was found in the control group (fractional anisotropy of the corpus callosum and corticospinal tracts: p. = 0.033 and p. = 0.022; radial diffusivity of the corpus callosum and corticospinal tracts: p. = 0.004 and p. = 0.008). Conversely, a significant increase of radial diffusivity was observed in the superior longitudinal fasciculi in both groups (p. = 0.02), indicating lack of treatment effects on this structure, showing damage progression likely due to a demyelination process.All these findings indicate the importance of administering, when possible, a rehabilitation treatment consisting of voluntary movements. We also demonstrated that the beneficial effects of a rehabilitation treatment are task-dependent and selective in their target; this becomes crucial towards the implementation of tailored rehabilitative approaches. © 2013 The Authors

    Disease-modifying therapies and coronavirus disease 2019 severity in multiple sclerosis

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    OBJECTIVE: This study was undertaken to assess the impact of immunosuppressive and immunomodulatory therapies on the severity of coronavirus disease 2019 (COVID-19) in people with multiple sclerosis (PwMS).METHODS: We retrospectively collected data of PwMS with suspected or confirmed COVID-19. All the patients had complete follow-up to death or recovery. Severe COVID-19 was defined by a 3-level variable: mild disease not requiring hospitalization versus pneumonia or hospitalization versus intensive care unit (ICU) admission or death. We evaluated baseline characteristics and MS therapies associated with severe COVID-19 by multivariate and propensity score (PS)-weighted ordinal logistic models. Sensitivity analyses were run to confirm the results.RESULTS: Of 844 PwMS with suspected (n = 565) or confirmed (n = 279) COVID-19, 13 (1.54%) died; 11 of them were in a progressive MS phase, and 8 were without any therapy. Thirty-eight (4.5%) were admitted to an ICU; 99 (11.7%) had radiologically documented pneumonia; 96 (11.4%) were hospitalized. After adjusting for region, age, sex, progressive MS course, Expanded Disability Status Scale, disease duration, body mass index, comorbidities, and recent methylprednisolone use, therapy with an anti-CD20 agent (ocrelizumab or rituximab) was significantly associated (odds ratio [OR] = 2.37, 95% confidence interval [CI] = 1.18-4.74, p =0.015) with increased risk of severe COVID-19. Recent use (<1month) of methylprednisolone was also associated with a worse outcome (OR = 5.24, 95% CI = 2.20-12.53, p =0.001). Results were confirmed by the PS-weighted analysis and by all the sensitivity analyses.INTERPRETATION: This study showed an acceptable level of safety of therapies with a broad array of mechanisms of action. However, some specific elements of risk emerged. These will need to be considered while the COVID-19 pandemic persists. ANN NEUROL 2021
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