Equazioni di II grado. Una classe si confronta con i testi storici

Nella presente tesi sono riassunte le diverse posizioni epistemologiche riguardo alla relazione tra didattica e storia della matematica, insieme alle possibili funzioni di quest'ultima nell'attività scolastica. In particolare ci si è soffermati sull'opportunità di introdurre gli studenti ad un rapporto diretto con le fonti storiche. A tale scopo è stata condotta una sperimentazione in una classe di seconda Liceo, a cui sono stati proposti tre brani di diversi autori e secoli da esaminare in gruppo. Sono stati dettagliatamente descritti e successivamente analizzati i comportamenti messi in atto dagli studenti alla lettura delle fonti.

Water, sediment and soil physicochemical interactions in freshwater, brackish and saline systems

The physicochemical interactions between water, sediment and soil deeply influence the formation and development of the ecosystem. In this research, different freshwater, brackish and saline subaqueous environments of Northern Italy were chosen as study area to investigate the physicochemical processes which occur at the interface between water and sediments, as well as the effects of soil submergence on ecosystem development. In the freshwater system of the Reno river basin, the main purpose was to define the heavy metals hazard in water and sediments of natural and artificial water courses. Heavy metals partitioning and speciation allowed to assess the environmental risk linked to the critical action of dredging canal sediments, for the maintenance of the hydraulic safety of plain lands. In addition, some bioremediation techniques were experimented for protecting sediments from heavy metals contamination, and for giving an answer to the problem of sediments management. In the brackish system of S. Vitale park, the development of hydromorphic and subaqueous soils was investigated. The study of soil profiles highlighted the presence of a soil continuum among pedons subjected to different saturation degrees. This investigation allowed to the identification of both morphological and physicochemical indicators, which characterize the formation of subaqueous soils and describe the soil hydromorphism in transitional soil systems. In the saline system of Grado lagoon, an ecosystem approach was used to define the role of water oscillation in soil characterization and plants colonization. This study highlighted the close relationship and the mutual influence of soil submergence and aeration, tide oscillation and vegetation cover, on the soil development. In view of climate change, this study contribute to understand and suppose how soil and landscape could evolve. However, a complete evaluation of hydromorphic soil functionality will be achieved only involving physiological and biochemical expertise in these kind of studies.

Modelli e strumenti di supporto alla scelta informata del paziente: un argine alla medicina difensiva

L’aumento esponenziale del contenzioso medico-legale – originatosi negli USA negli anni Sessanta in proporzioni tali da far parlare di medical liability crisis, e sviluppatosi in Italia a partire dalla metà degli anni Ottanta – ha comportato e continua a comportare, unitamente ad altre conseguenze negative, il ricorso sempre più frequente dei sanitari alle pratiche di medicina difensiva, con elevatissimi costi a carico del Servizio Sanitario Nazionale dovuti alla sovrabbondanza di trattamenti e ricoveri inutili e di procedure diagnostiche invasive non necessarie, peraltro produttive di stress emotivo nei pazienti. La causa dell’aumento della litigiosità deve essere ricercata in buona parte nella relazione medico-paziente, in particolar modo con riferimento al momento informativo che precede l’acquisizione del consenso informato al trattamento clinico. In Italia, i limiti che per lo più caratterizzano gli studi riguardanti il consenso informato derivano principalmente dal fatto che essi tendono a focalizzarsi unicamente sulla componente scritta del medesimo. Il fulcro del consenso informato, invece, deve ritenersi rappresentato da una comunicazione tra sanitario e paziente relativa ad un trattamento proposto ed alle possibili alternative, alla non sottoposizione ad alcun trattamento e ai rischi e benefici di ciascuna di queste opzioni. In un tale contesto il tema della comunicazione tra il professionista e la persona assistita sta suscitando interesse poiché ci si aspetta che esso conduca a miglioramenti degli outcome dei pazienti e alla diminuzione delle denunce da parte di questi ultimi per casi di responsabilità sanitaria. La maggiore attenzione al rapporto medico - paziente ha fatto emergere il bisogno di migliorare e potenziare le abilità comunicative dei medici, in un’ottica in cui il momento comunicativo possa essere percepito dal professionista come fulcro del rapporto medico-paziente, nella prospettiva di una elaborazione di strategie di prevenzione e contrasto ai fenomeni di medicina difensiva.

Evaluation zellulärer Mechanismen der allergen-spezifischen Immuntherapie in einem chronischen Modell der allergischen Atemwegsentzündung

Klinische Studien haben gezeigt, dass die allergenspezifische Immuntherapie (SIT) eine effektive Therapieoption für allergische Erkrankungen ist. Obwohl dieses Therapieverfahren seit über 100 Jahren existiert, sind die zugrunde liegenden Suppressionsmechanismen jedoch nicht vollständig verstanden. Bisher wird angenommen, dass der Behandlungserfolg der SIT auf einer Blockade durch allergenspezifische Antikörper, einer Verschiebung des Th1-Th2-Gleichgewichtes und/oder auf einer Suppression durch regulatorische T-Zellen (Tregs) basiert. Um die Effekte der SIT in einer chronischen Erkrankung in vivo untersuchen zu können, wurde in dieser Doktorarbeit ein Mausmodell für chronisches Asthma entwickelt, das die Situation im Menschen nach einer SIT nachahmt. rnDurch eine SIT war es möglich, allergeninduzierte Asthmasymptome wie Atemwegshyperreagibilität (AHR), Eosinophilie in der Lunge, IgE-Produktion und Atemwegsentzündung im Modell zu unterdrücken. Bemerkenswert ist, dass durch OVA-spezifische Immuntherapie (OVA-IT) ebenfalls eine Verringerung der strukturellen Veränderungen im Lungengewebe im chronischen Krankheitsverlauf erreicht wurde.rnDes Weiteren wurde in diesem Modell nach den Prozessen gesucht, die für die toleranzinduzierende Wirkung der SIT verantwortlich sein können. Dabei wurde im Vergleich zur Placebo-behandelten Gruppe eine erhöhte Antwort spezifischer IgG1-Antikörper, eine verstärkte Th1-Antwort, sowie eine erhöhte Frequenz von FoxP3+ Tregs und von IL-10-produzierenden T-Zellen (Tr1-Zellen) nach OVA-IT festge-stellt. Zur weiteren Untersuchung der von SIT-induzierten T-Zellantworten wurden Mausmodelle des allergischen Asthmas mit einem akuten Verlauf gewählt.rnDie Bedeutung der Th1-Zellen für die SIT wurde in T-bet-/- Mäusen untersucht, welche aufgrund des Fehlens des Transkriptionsfaktors T-bet keine stabile Th1-Antwort induzieren können. Durch SIT war es möglich, allergeninduzierte Asthmasymptome wie AHR, eosinophile Granulozyten in der Lunge, IgE-Produktion und Atemwegsentzündung in den T-bet-/- Tieren im gleichen Maße wie in den Wildtyptieren zu unterdrücken. Diese Untersuchung zeigte, dass die SIT auch ohne funktionelle Th1-Zellen die allergische Entzündung unterdrücken kann. rnDie Rolle der Tregs für die SIT wurde in DO11.10 Mäusen und DO11.10 RAG-/- Mäusen untersucht. In beiden Stämmen konnte nach SIT eine Induktion OVA-spezifischer Tregs nachgewiesen werden. In DO11.10 RAG-/- Mäusen können durch den Knockout im rag2-Gen keine natürlichen, d.h. im Thymus gereiften, Tregs entstehen. Im Blut von DO11.10 RAG-/- Mäusen war direkt nach Durchführung der OVA-IT eine FoxP3+ Treg-Population detektierbar. Demnach wird durch die OVA-IT eine de-novo-Induktion von FoxP3+ Tregs in Gang gesetzt. In Abwesenheit der natürlichen Tregs zeigte sich weiterhin, dass diese Zellen zur Produktion von IL-10 in T-Zellen und somit zum Erfolg der SIT beitragen.rnDie Rolle der FoxP3+ Tregs bei der SIT wurde in DEREG Mäusen untersucht. Eine Depletion der FoxP3+ Tregs in DEREG Mäusen während der Durchführung der OVA-IT hob die protektiven Effekte der Therapie jedoch nur teilweise auf. rnUm die Rolle des regulatorischen Zytokins IL-10 bei der SIT zu untersuchen, wurde ein blockierender Antikörper gegen den IL-10-Rezeptor (anti-IL-10R) im chronischen Modell des allergischen Asthmas mit SIT angewendet. Anti-IL-10R hob die protektive Wirkung der SIT auf die AHR, die Atemwegsentzündung und die strukturellen Veränderungen im Lungengewebe auf. Somit ist die protektive Wirkung der SIT abhängig vom IL-10-Signalweg.rnZusammenfassend stellt diese Arbeit die Bedeutung der SIT für allergische Erkrankungen heraus. SIT kann durch die positive Beeinflussung der allergiebedingten, strukturellen Veränderungen in der Lunge auch für Asthmapatienten große Vorteile bringen. Die aus Studien bekannten Mechanismen konnten im Modell bestätigt werden und wurden im weiteren Verlauf untersucht. Die Arbeit stellt im Besonderen die Bedeutung der IL-10-produzierenden und FoxP3+ Tregs für die Effektivität der SIT in den Vordergrund. Zudem ist durch die Etablierung eines neuen Mausmodells der SIT für chronisches allergisches Asthma ein Mittel zur weiteren Erforschung der zugrunde liegenden Prozesse dieser erfolgreichen Therapie geschaffen worden. rn

Actinobaculum schaalii an emerging pediatric pathogen?

Background Actinobaculum schaalii was first described as a causative agent for human infection in 1997. Since then it has mainly been reported causing urinary tract infections (UTI) in elderly individuals with underlying urological diseases. Isolation and identification is challenging and often needs molecular techniques. A. schaalii is increasingly reported as a cause of infection in humans, however data in children is very limited. Case presentation We present the case of an 8-month-old Caucasian boy suffering from myelomeningocele and neurogenic bladder who presented with a UTI. An ultrasound of the urinary tract was unremarkable. Urinalysis and microscopy showed an elevated leukocyte esterase test, pyuria and a high number of bacteria. Empiric treatment with oral co-trimoxazole was started. Growth of small colonies of Gram-positive rods was observed after 48 h. Sequencing of the 16S rRNA gene confirmed an A. schaalii infection 9 days later. Treatment was changed to oral amoxicillin for 14 days. On follow-up urinalysis was normal and urine cultures were negative. Conclusions A.schaalii is an emerging pathogen in adults and children. Colonization and subsequent infection seem to be influenced by the age of the patient. In young children with high suspicion of UTI who use diapers or in children who have known abnormalities of their urogenital tract, infection with A. schaalii should be considered and empiric antimicrobial therapy chosen accordingly.

In vitro evaluation of differences in phase 1 metabolism of ketamine and other analgesics among humans, horses, and dogs

OBJECTIVE: To investigate cytochrome P450 (CYP) enzymes involved in metabolism of racemic and S-ketamine in various species and to evaluate metabolic interactions of other analgesics with ketamine. SAMPLE POPULATION: Human, equine, and canine liver microsomes. PROCEDURES: An analgesic was concurrently incubated with luminogenic substrates specific for CYP 3A4 or CYP 2C9 and liver microsomes. The luminescence signal was detected and compared with the signal for negative control samples. Ketamine and norketamine enantiomers were determined by use of capillary electrophoresis. RESULTS: A concentration-dependent decrease in luminescence signal was detected for ibuprofen and diclofenac in the assay for CYP 2C9 in human and equine liver microsomes but not in the assay for CYP 3A4 and methadone or xylazine in any of the species. Coincubation of methadone or xylazine with ketamine resulted in a decrease in norketamine formation in equine and canine liver microsomes but not in human liver microsomes. In all species, norketamine formation was not affected by ibuprofen, but diclofenac reduced norketamine formation in human liver microsomes. A higher rate of metabolism was detected for S-ketamine in equine liver microsomes, compared with the rate for the S-enantiomer in the racemic mixture when incubated with any of the analgesics investigated. CONCLUSIONS AND CLINICAL RELEVANCE: Enzymes of the CYP 3A4 family and orthologs of CYP 2C9 were involved in ketamine metabolism in horses, dogs, and humans. Methadone and xylazine inhibited in vitro metabolism of ketamine. Therefore, higher concentrations and diminished clearance of ketamine may cause adverse effects when administered concurrently with other analgesics.

Psychoendocrine validation of a short measure for assessment of perceived stress management skills in different non-clinical populations

BACKGROUND: We investigated the psychometric properties of a short questionnaire for combined assessment of different perceived stress management skills in the general population and tested whether scores relate to physiological stress reactivity. METHODS: For psychometric evaluation, we determined the factor structure of the questionnaire and investigated its measurement invariance in the participant groups and over time in three different independent samples representing the general population (total N=332). Reliability was tested by estimating test-retest reliability, internal consistency, and item reliabilities. We examined convergent and criterion validity using selected criterion variables. For endocrine validation, 35 healthy non-smoking and medication-free men in a laboratory study and 35 male and female employees in a workplace study underwent an acute standardized psychosocial stress task. We assessed stress management skills and measured salivary cortisol before and several times up to 60 min (workplace study) and 120 min (laboratory study) after stress. Potential confounders were controlled. RESULTS: The factor structure of the questionnaire consists of five scales reflecting acceptably distinct stress management skills such as cognitive strategies, use of social support, relaxation strategies, anger regulation, and perception of bodily tension. This factor structure was stable across participant groups and over time. Internal consistencies, item reliabilities, and test-retest reliabilities met established statistical requirements. Convergent and criterion validity were also established. In both endocrine validation studies, higher stress management skills were independently associated with lower cortisol stress reactivity (p's<.029). CONCLUSIONS: Our findings suggest that the questionnaire has good psychometric properties and that it relates to subjective psychological and objective physiological stress indicators. Therefore, the instrument seems a suitable measure for differential assessment of stress management skills in the general population.

Glucocorticoids enhance in vivo exposure-based therapy outcome in spider phobia

BACKGROUND: Preclinical and clinical studies indicate that the administration of glucocorticoids may promote fear extinction processes. In particular, it has been shown that glucocorticoids enhance virtual reality based exposure therapy of fear of heights. Here, we investigate whether glucocorticoids enhance the outcome of in vivo exposure-based group therapy of spider phobia. METHODS: In a double blind, block-randomized, placebo-controlled, between-subject study design, 22 patients with specific phobia of spiders were treated with two sessions of in vivo exposure-based group therapy. Cortisol (20 mg) or placebo was orally administered 1 hr before each therapy session. Patients returned for a follow-up assessment one month after therapy. RESULTS: Exposure-based group therapy led to a significant decrease in phobic symptoms as assessed with the Fear of Spiders Questionnaire (FSQ) from pretreatment to immediate posttreatment and to follow-up. The administration of cortisol to exposure therapy resulted in increased salivary cortisol concentrations and a significantly greater reduction in fear of spiders (FSQ) as compared to placebo at follow-up, but not immediately posttreatment. Furthermore, cortisol-treated patients reported significantly less anxiety during standardized exposure to living spiders at follow-up than placebo-treated subjects. Notably, groups did not differ in phobia-unrelated state-anxiety before and after the exposure sessions and at follow-up. CONCLUSIONS: These findings indicate that adding cortisol to in vivo exposure-based group therapy of spider phobia enhances treatment outcome.

Evaluative Morphology in Georgian

With examples drawn from over 200 world languages, this ground-breaking volume presents a state-of-the-art overview of evaluative morphology. Offering an innovative approach to major theoretical questions, the Edinburgh Handbook analyses the field from a cross-linguistic perspective, considering semantic, pragmatic and sociolinguistic aspects, as well as word-formation processes and evaluative morphology acquisition. Complementing the synchronic approach with a diachronic perspective, this study establishes a picture of intriguing diversity in evaluative morphology manifestations, and offers a comprehensive analysis of the situation in dozens of languages and language families. Divided into 2 distinct parts, the handbook begins with 13 chapters discussing evaluative morphology in relation to areas such as pragmatics, semantics, linguistic universals and sociolinguistics. The second part is comprised of descriptive chapters, broken into the following subsets: Eurasia, South- East Asia and Oceania, Australia-New Guinea, Africa, North America and South America.

Stress-induced cortisol secretion impairs detection performance in x-ray baggage screening for hidden weapons by screening novices

Aviation security strongly depends on screeners' performance in the detection of threat objects in x-ray images of passenger bags. We examined for the first time the effects of stress and stress-induced cortisol increases on detection performance of hidden weapons in an x-ray baggage screening task. We randomly assigned 48 participants either to a stress or a nonstress group. The stress group was exposed to a standardized psychosocial stress test (TSST). Before and after stress/nonstress, participants had to detect threat objects in a computer-based object recognition test (X-ray ORT). We repeatedly measured salivary cortisol and X-ray ORT performance before and after stress/nonstress. Cortisol increases in reaction to psychosocial stress induction but not to nonstress independently impaired x-ray detection performance. Our results suggest that stress-induced cortisol increases at peak reactivity impair x-ray screening performance.

A cysteine protease inhibitor of plasmodium berghei is essential for exo-erythrocytic development

Plasmodium parasites express a potent inhibitor of cysteine proteases (ICP) throughout their life cycle. To analyze the role of ICP in different life cycle stages, we generated a stage-specific knockout of the Plasmodium berghei ICP (PbICP). Excision of the pbicb gene occurred in infective sporozoites and resulted in impaired sporozoite invasion of hepatocytes, despite residual PbICP protein being detectable in sporozoites. The vast majority of these parasites invading a cultured hepatocyte cell line did not develop to mature liver stages, but the few that successfully developed hepatic merozoites were able to initiate a blood stage infection in mice. These blood stage parasites, now completely lacking PbICP, exhibited an attenuated phenotype but were able to infect mosquitoes and develop to the oocyst stage. However, PbICP-negative sporozoites liberated from oocysts exhibited defective motility and invaded mosquito salivary glands in low numbers. They were also unable to invade hepatocytes, confirming that control of cysteine protease activity is of critical importance for sporozoites. Importantly, transfection of PbICP-knockout parasites with a pbicp-gfp construct fully reversed these defects. Taken together, in P. berghei this inhibitor of the ICP family is essential for sporozoite motility but also appears to play a role during parasite development in hepatocytes and erythrocytes.

Facial Nerve Image Enhancement from CBCT using Supervised Learning Technique

Facial nerve segmentation plays an important role in surgical planning of cochlear implantation. Clinically available CBCT images are used for surgical planning. However, its relatively low resolution renders the identification of the facial nerve difficult. In this work, we present a supervised learning approach to enhance facial nerve image information from CBCT. A supervised learning approach based on multi-output random forest was employed to learn the mapping between CBCT and micro-CT images. Evaluation was performed qualitatively and quantitatively by using the predicted image as input for a previously published dedicated facial nerve segmentation, and cochlear implantation surgical planning software, OtoPlan. Results show the potential of the proposed approach to improve facial nerve image quality as imaged by CBCT and to leverage its segmentation using OtoPlan.

Insulin activates Na(+)/H(+) exchanger 3: biphasic response and glucocorticoid dependence.

Insulin is an important regulator of renal salt and water excretion, and hyperinsulinemia has been implicated to play a role in hypertension. One of the target proteins of insulin action in the kidney is Na(+)/H(+) exchanger 3 (NHE3), a principal Na(+) transporter responsible for salt absorption in the mammalian proximal tubule. The molecular mechanisms involved in activation of NHE3 by insulin have not been studied so far. In opossum kidney (OK) cells, insulin increased Na(+)/H(+) exchange activity in a time- and concentration-dependent manner. This effect is due to activation of NHE3 as it persisted after pharmacological inhibition of NHE1 and NHE2. In the early phase of stimulation (2-12 h), NHE3 activity was increased without changes in NHE3 protein and mRNA. At 24 h, enhanced NHE3 activity was accompanied by an increase in total and cell surface NHE3 protein and NHE3 mRNA abundance. All the effects of insulin on NHE3 activity, protein, and mRNA were amplified in the presence of hydrocortisone. These results suggest that insulin stimulates renal tubular NHE3 activity via a biphasic mechanism involving posttranslational factors and an increase in NHE3 gene expression and the effects are dependent on the permissive action of hydrocortisone.