Identification of optimal locomotion architectures for multi-legged walking rovers with genetic algorithm

LAUREA MAGISTRALEI rover spaziali in grado di operare autonomamente sono una tecnologia chiave nello sviluppo dell’industria spaziale. La capacità di operare senza intervento umano è di fondamentale importanza in ambienti ostili come quelli presenti al di fuori dell’atmosfera terrestre. In particolare, lo sviluppo di rover a zampe risulta di notevole interesse in quanto vantano performance migliori in terreni sconnessi rispetto ai rover a ruote. Sfortunatamente, gli scienziati non sono ancora giunti a un consenso su quale sia l’architettura migliore per i rover a zampe e sul numero ottimale di zampe da utilizzare. Attualmente diverse architetture vengono utilizzate e la gran parte di esse sono ispirate dalla natura. Tuttavia non è mai stato compiuto un confronto esaustivo tra le diverse configurazioni. L’obiettivo di questa tesi è l’identificazione dell’architettura ottimale tramite l’ottimizzazione di un parametro di merito. L’ottimizzazione è ripetuta su rover con un diverso numero di zampe. Ciò è fatto per valutare quale effetto abbia la variazione del numero di gambe sulle prestazioni del rover. Inizialmente viene definita una funzione che permette di passare dall’architettura generica del rover ai parametri di merito. I parametri di merito considerati sono legati alla stabilità del rover e agli ellissoidi di manovrabilità delle zampe. Successivamente, la funzione definita precedentemente viene ottimizzata con l’algoritmo genetico. E’ stato scelto l’algoritmo genetico in quanto è un processo simile all’evoluzione naturale. I risultati ottenuti sono infine confrontati per comprendere come le prestazioni cambino a seconda delle diverse configurazioni ottenute. In particolare viene studiata l’evoluzione dei parametri di merito durante la traiettoria.Autonomous space rovers are a key technology in the development of the space industry. The ability to carry on operations without human assistance is fundamental in harsh environments such as the ones found outside the Earth atmosphere. The development of legged rovers is of particular interest, given their superior performance in the crossing of not smooth surfaces in comparison to wheeled rovers. Unfortunately, scientists still have to find a consensus on the best architecture of legged rovers and on the number of legs to use. Nowadays, many different architectures are used and most of them are directly inspired by nature, but no exhaustive comparison has been carried on among them. The objective of this thesis is the identification of the best architecture via an optimisation of a performance parameter. The optimisation is repeated for rovers with different number of legs, in order to assess also how the increase of number of legs affects the rover performances. The results are achieved by defining a function able to link a general architecture for the legged rover to the defined performance parameters. The parameters are related to the stability of the rover and to the manipulability ellipsoids of the legs. Then, the aforementioned function is optimised via the genetic algorithm, which is chosen for its similarity to natural evolution. The results achieved are shown and confronted in order to understand how different configurations compare with each other. Particularly, the evolution of the performance parameters along the trajectory is object of study

Simultaneous inhibition of B7 and LFA-1 signaling prevents rejection of discordant neural xenografts in mice lacking CD40L.

Transplantation of embryonic human neural tissue can restore dopamine neurotransmission and improve neurological function in patients with Parkinson's disease. Logistical and ethical factors limit the availability of human embryonic allogeneic tissue. Embryonic xenogeneic neural tissue from porcine donors is an alternative form of donor tissue, but effective immunomodulatory techniques are warranted for neural xenotransplantation to become clinically feasible. We transplanted embryonic porcine ventral mesencephalic tissue into the brains of adult untreated C57BL/6 mice, untreated CD40L-/-mice and CD40L-/-mice that received injections of anti-LFA-1, CTLA41g or both compounds. Double-treated CD40L-/-mice had large grafts with high numbers of dopaminergic neurons 4 wk after transplantation. The grafts were completely devoid of lymphocytes, macrophages and activated microglia. Untreated C57BL/6 mice had rejected their grafts. Untreated CD40L-/-mice and CD40L-/-mice treated with monotherapy of anti-LFA-1 or CTLA41g had smaller grafts and more microglial and lymphocytic infiltration than double-treated CD40L-/-mice. We conclude that immunomodulation with concomitant inhibition of LFA-1 and B7 signaling in the perioperative period in CD40L-/-mice prevented the rejection of discordant neural xenografts. The treatment most likely reduced antigen presenting capacity and interfered with the costimulatory signaling needed for T cell activation to occur

No-Restraint Committed General Hospital Psychiatric Units (SPDCs) in Italy—A Descriptive Organizational Study

This study describes and explores the application of no-restraint policies in General Hospital Psychiatric Units (GHPUs) in Italy, a country pioneering in deinstitutionalization and psychiatric reform. The research aims to assess the organizational characteristics and effectiveness of no-restraint practices, contributing to the global discourse on humane psychiatric care. Following a purposive sampling approach, a nationwide descriptive study was conducted involving a detailed online survey distributed to 24 GHPUs actively engaged in or aspiring toward no-restraint practices. The survey, comprising 60 items across seven sections, gathered comprehensive data on the structural, organizational, and operational dimensions of the units, along with the prevalence and management of restraint episodes. Results reveal a significant commitment to no-restraint policies, with 14 GHPUs reporting zero restraint incidents in 2022. Despite variations in infrastructure and staffing, a common thread was the implementation of systematic procedures and risk management training aimed at reducing coercive practices. The study identified a correlation between the use of exclusive garden spaces and an increased incidence of restraints, suggesting nuanced factors influencing restraint practices. The findings underscore the viability and ethical alignment of no-restraint practices within psychiatric care, highlighting the crucial role of organizational protocols and training. This research adds empirical weight to the advocacy for restraint-free environments in mental health settings, signaling a paradigm shift toward more humane and rights-respecting psychiatric care

Ischemia-Reperfusion Injury and Pregnancy Initiate Time-Dependent and Robust Signs of Up-Regulation of Cardiac Progenitor Cells

To explore how cardiac regeneration and cell turnover adapts to disease, different forms of stress were studied for their effects on the cardiac progenitor cell markers c-Kit and Isl1, the early cardiomyocyte marker Nkx2.5, and mast cells. Adult female rats were examined during pregnancy, after myocardial infarction and ischemia-reperfusion injury with/out insulin like growth factor-1(IGF-1) and hepatocyte growth factor (HGF). Different cardiac sub-domains were analyzed at one and two weeks post-intervention, both at the mRNA and protein levels. While pregnancy and myocardial infarction up-regulated Nkx2.5 and c-Kit (adjusted for mast cell activation), ischemia-reperfusion injury induced the strongest up-regulation which occurred globally throughout the entire heart and not just around the site of injury. This response seems to be partly mediated by increased endogenous production of IGF-1 and HGF. Contrary to c-Kit, Isl1 was not up-regulated by pregnancy or myocardial infarction while ischemia-reperfusion injury induced not a global but a focal up-regulation in the outflow tract and also in the peri-ischemic region, correlating with the up-regulation of endogenous IGF-1. The addition of IGF-1 and HGF did boost the endogenous expression of IGF and HGF correlating to focal up-regulation of Isl1. c-Kit expression was not further influenced by the exogenous growth factors. This indicates that there is a spatial mismatch between on one hand c-Kit and Nkx2.5 expression and on the other hand Isl1 expression. In conclusion, ischemia-reperfusion injury was the strongest stimulus with both global and focal cardiomyocyte progenitor cell marker up-regulations, correlating to the endogenous up-regulation of the growth factors IGF-1 and HGF. Also pregnancy induced a general up-regulation of c-Kit and early Nkx2.5+ cardiomyocytes throughout the heart. Utilization of these pathways could provide new strategies for the treatment of cardiac disease

Effectiveness of lithium in subjects with treatment-resistant depression and suicide risk: results and lessons of an underpowered randomised clinical trial

BACKGROUND: As lithium treatment might be effective in reducing the risk of deliberate self-harm (DSH) in adult patients with unipolar affective disorders, we designed a pragmatic randomised trial to assess its efficacy in more than 200 patients with treatment-resistant depression. However, we randomised 56 patients only. The aim of this report is therefore twofold: first, to disseminate the results of this underpowered study which may be incorporated into future meta-analytical reviews; second, to analyse some critical aspects of the study which might explain failure to reach the target sample size.METHODS: We carried out a randomised, parallel group, assessor-blinded superiority clinical trial. Adults with a diagnosis of major depression, an episode of DSH in the previous 12 months and inadequate response to at least two antidepressants given sequentially at an adequate dose for an adequate time for the current depressive episode were allocated to add lithium to usual care (intervention arm) versus usual care alone (control arm). Suicide completion and acts of DSH during the 12 months of follow-up constituted the composite primary outcome.RESULTS: Of 58 patients screened for inclusion, 29 were allocated to lithium plus usual care and 27 were assigned to usual care without lithium. Six patients in the lithium plus usual care group and seven in the usual care group committed acts of DSH during the follow-up phase. The survival probability did not differ between the two treatment arms (Chi2 = 0.17, p =0.676). With regard to changes in the severity of depressive symptomatology from baseline to endpoint, no significant differences were detected.CONCLUSIONS: The present study failed to achieve the minimum sample size needed to detect a clinically meaningful difference between the two treatment arms. Consequently, the finding that lithium, in addition to usual care, did not exert a positive effect in terms of reduction of DSH after 12 months of follow-up is likely due to the lack of sufficient statistical power to detect a difference, if a difference existed. The dissemination of the results of this underpowered study will inform future meta-analytical reviews on lithium and suicide-related outcomes.TRIAL REGISTRATION: ClinicalTrials.gov identifier: NCT00927550

Подбор оборудования для эксплуатации нефтяной скважины

Результат исследования: Был подобран погружной электроцентробежный насос, для данной нефтяной скважины, достоинствами которого является простота конструкции, так же унифицированная база запасных частей и комплектующих изделий отечественного производства.Result of the research: A submersible electric centrifugal pump was selected, for this oil well, whose advantages are simplicity of designs, as well as a unified base of spare parts and components of domestic production

Induction of operational tolerance to allografts and xenografts

Inhibition of the costimulatory molecules B7 and CD40L with CTLA4Ig and anti-CD40L administered only during the first week after transplantation induces indefinite survival of allo- and xenogeneic heart transplants and significantly prolongs skin grafts in C3H mice. However, this treatment protocol is not as effective in C57BL/6 mice which reject skin transplants with nearly the same median survival time as untreated controls. This has been shown to be due to the ability of CD8+ T cells to be activated autonomously of B7 or CD40L costimulation. LFA-1 is an important signaling molecule for CD8+ T cell function and we therefore hypothesized that its inhibition may compliment B7 and CD40L blockade and induce indefinite survival of transplants in mice. Anti-LFA-1 combined with CTLA4Ig induced indefinite survival of heart transplants after one week of treatment. Anti-LFA-1 also prevented immune responses and chronic vasculopathy in CD40L -/- mice. When CTLA4Ig was combined with anti-LFA-1 and given to CD40L -/- mice, dopaminergic porcine xenografts were accepted without any signs of rejection. The combination of anti-CD40L, CTLA4Ig and anti-LFA-1 induced permanent acceptance of dopaminergic porcine grafts in wild-type C57BL/6 mice. Surprisingly these recipients could be induced to rejected their grafts if challenged with glia cells of donor origin indicating that regulatory T cells maybe involved in the acceptance of these transplants. In order to ascertain the importance of regulatory T cells, IL-10 deficient mice were transplanted with allogeneic heart transplants and treated with costimulation blockade. A majority of these hearts stopped beating two days after transplantation succumbing to a massive neutrophilic infiltrate resembling myocardial infarction. The remaining hearts were rejected with in 50 days after transplantation. These results indicate that anti-LFA-1 can compliment CTLA4Ig and anti-CD40L in the induction of operational tolerance and that this state is facilitated by IL-10 and indirectly regulatory T cells