146 research outputs found

    Anxiety and Performance: An Endogenous Learning-by-doing Model

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    In this article, we show that a standard economic model, the endogenous learning-by-doing model, captures several major themes from the anxiety literature in psychology. In our model, anxiety is a fully endogenous construct that can be separated naturally into its cognitive and physiological components. As such, our results are directly comparable with hypotheses and evidence from psychology. We show that anxiety can serve a motivating function, which suggests potential applications in the principal-agent literature.Diamond Paradox, price dispersion, search, strategic complementarities

    Agency and Anxiety

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    In this paper, we introduce the psychological concept of anxiety into agency theory. An important benchmark in the anxiety literature is the inverted-U hypothesis which states that an increase in anxiety improves performance when anxiety is low but reduces it when anxiety is high. We consider a version of the Holmstrom-Milgrom linear principal-agent model where the agent conforms to the inverted-U hypothesis and investigate the nature of the optimal linear contract. We find that although high-powered incentives can be demotivational, a profit-maximizing principal never offers them. In contrast, the principal may optimally engage in a demotivational level of monitoring. Moreover, since risk can be motivational, the principal may refrain from eliminating it even when monitoring is costless. Indeed, the principal may even add pure noise to the contract in order to motivate the agent, contradicting the informativeness principle. Finally, incentives and monitoring can be strategic substitutes or complements in our model.

    Practice Recommendations for Diagnosis and Treatment of the Most Common Forms of Secondary Hypertension

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    The vast majority of hypertensive patients are never sought for a cause of their high blood pressure, i.e. for a \u2018secondary\u2019 form of arterial hypertension. This under detection explains why only a tiny percentage of hypertensive patients are ultimately diagnosed with a secondary form of arterial hypertension. The prevalence of these forms is, therefore, markedly underestimated, although, they can involve as many as one-third of the cases among referred patients and up to half of those with difficult to treat hypertension. The early detection of a secondary form is crucial, because if diagnosed in a timely manner, these forms can be cured at long-term, and even when cure cannot be achieved, their diagnosis provides a better control of high blood pressure, and allows prevention of hypertension-mediated organ damage, and related cardiovascular complications. Enormous progress has been made in the understanding, diagnostic\ua0work-up, and management of secondary hypertension in the last decades. The\ua0aim of this minireview is, therefore, to provide updated concise information on the screening, diagnosis, and management of the most common forms, including primary aldosteronism, renovascular hypertension, pheochromocytoma and paraganglioma, Cushing\u2019s syndrome, and obstructive sleep apnea

    A causal statistical family of dissipative divergence type fluids

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    In this paper we investigate some properties, including causality, of a particular class of relativistic dissipative fluid theories of divergence type. This set is defined as those theories coming from a statistical description of matter, in the sense that the three tensor fields appearing in the theory can be expressed as the three first momenta of a suitable distribution function. In this set of theories the causality condition for the resulting system of hyperbolic partial differential equations is very simple and allow to identify a subclass of manifestly causal theories, which are so for all states outside equilibrium for which the theory preserves this statistical interpretation condition. This subclass includes the usual equilibrium distributions, namely Boltzmann, Bose or Fermi distributions, according to the statistics used, suitably generalized outside equilibrium. Therefore this gives a simple proof that they are causal in a neighborhood of equilibrium. We also find a bigger set of dissipative divergence type theories which are only pseudo-statistical, in the sense that the third rank tensor of the fluid theory has the symmetry and trace properties of a third momentum of an statistical distribution, but the energy-momentum tensor, while having the form of a second momentum distribution, it is so for a different distribution function. This set also contains a subclass (including the one already mentioned) of manifestly causal theories.Comment: LaTex, documentstyle{article

    Clinical Evidence of Type 2 Inflammation in Non-allergic Rhinitis with Eosinophilia Syndrome: a Systematic Review

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    Purpose of Review: Non-allergic rhinitis (NAR) includes different subtypes, among which NAR with eosinophilia syndrome (NARES) is the most important because of severity of symptoms and the high risk of comorbidities. Its pathophysiology is still object of debate, but a crucial role of chronic eosinophilic inflammation has been recognized. The aim of this review is to critically analyze the current evidence regarding the hypothesis that NARES may be considered a type 2 inflammatory disorder. Recent Findings: The definition and diagnostic criteria for NARES are not universally shared and adopted, thus generating difficulties in reproducing the results. At present, there is extreme heterogeneity in sampling methods and disagreement in the cut-off of local eosinophilic count to determine a diagnosis of NARES. The PRISMA (Preferred Reporting Items for Systematic Reviews and Meta-Analyses) standard was applied to identify English-language experimental and clinical articles regarding NARES. The search was performed in April 2021. Twenty-six articles were included. Summary: Our data suggest a particular heterogeneity regarding sampling and specific cut-offs adopted for diagnosis of NARES and consensus should be reached. We suggest that eosinophil count should be reported as an absolute value for at least 10 observed rich fields in order to increase the level of standardization. Consensus among authors on this topic should be reached with particular attention to the cut-off for diagnosis. In the future, this limitation may be overcome by the identification of repeatable biomarkers to refine diagnosis and prognosis of NARES. Furthermore, our data strongly suggest that NARES have numerous similarities with clinical features of the most common type 2 diseases such as eosinophilic asthma and chronic rhinosinusitis with nasal polyps (CRSwNP): late onset, association with type 2 comorbidities, selective eosinophilic tissue infiltration, remarkable response to oral and intranasal corticosteroids, and progression in a type 2 CRSwNP

    Secondary cytomegalovirus infections: How much do we still not know? Comparison of children with symptomatic congenital cytomegalovirus born to mothers with primary and secondary infection

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    congenital cytomegalovirus (cCMV) infection can follow primary and secondary maternal infection. growing evidence indicate that secondary maternal infections contribute to a much greater proportion of symptomatic cCMV than was previously thought. We performed a monocentric retrospective study of babies with cCMV evaluated from august 2004 to february 2021; we compared data of symptomatic children born to mothers with primary or secondary infection, both at birth and during follow up. among the 145 babies with available data about maternal infection, 53 were classified as having symptomatic cCMV and were included in the study: 40 babies were born to mothers with primary infection and 13 babies were born to mothers with secondary infection. Analyzing data at birth, we found no statistical differences in the rate of clinical findings in the two groups, except for unilateral sensorineural hearing loss (SNHL) which was significantly more frequent in patients born to mother with secondary infection than in those born to mother with primary infection (46.2 vs. 17.5%, P = 0.037). during follow up, we found a higher rate of many sequelae (tetraparesis, epilepsy, motor and speech delay, and unilateral SNHL) in the group of children born to mothers with secondary infection, with a statistical difference for tetraparesis and unilateral SNHL. otherwise, only children born to mothers with primary infection presented bilateral SNHL both at birth and follow up. Our data suggest that the risk of symptomatic cCMV and long-term sequelae is similar in children born to mother with primary and secondary CMV infection; it is important to pay appropriate attention to seropositive mothers in order to prevent reinfection and to detect and possibly treat infected babies

    Gastrointestinal stromal tumour of the duodenum in childhood: a rare case report

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    <p>Abstract</p> <p>Background</p> <p>Gastrointestinal stromal tumours (GISTs) are uncommon primary mesenchymal tumours of the gastrointestinal tract mostly observed in the adults. Duodenal GISTs are relatively rare in adults and it should be regarded as exceptional in childhood. In young patients duodenal GISTs may be a source of potentially lethal haemorrhage and this adds diagnostic and therapeutic dilemmas to the concern about the long-term outcome.</p> <p>Case presentation</p> <p>A 14-year-old boy was referred to our hospital with severe anaemia due to recurrent episodes of upper gastrointestinal haemorrhage. Endoscopy, small bowel series, scintigraphy and video capsule endoscopy previously done elsewhere were negative. Shortly after the admission, the patient underwent emergency surgery for severe recurrence of the bleeding. At surgery, a 4 cm solid mass arising from the wall of the fourth portion of the duodenum was identified. The invasion and the erosion of the duodenal mucosa was confirmed by intra-operative pushed duodenoscopy. The mass was resected by a full-thickness duodenal wall excision with adequate grossly free margins. Immunohistochemical analysis of the specimen revealed to be positive for CD117 (c-KIT protein) consistent with a diagnosis of GIST. The number of mitoses was < 5/50 HPF. Mutational analysis for c-KIT/PDGFRA tyrosine kinase receptor genes resulted in a wildtype pattern. The patient had an uneventful course and he has remained disease-free during two years of follow-up.</p> <p>Conclusion</p> <p>Duodenal GISTs in children are very rare and may present with massive bleeding. Cure can be achieved by complete surgical resection, but even in the low-aggressive tumours the long-term outcome may be unpredictable.</p

    Comparison Study of MS-HRM and Pyrosequencing Techniques for Quantification of APC and CDKN2A Gene Methylation

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    There is increasing interest in the development of cost-effective techniques for the quantification of DNA methylation biomarkers. We analyzed 90 samples of surgically resected colorectal cancer tissues for APC and CDKN2A promoter methylation using methylation sensitive-high resolution melting (MS-HRM) and pyrosequencing. MS-HRM is a less expensive technique compared with pyrosequencing but is usually more limited because it gives a range of methylation estimates rather than a single value. Here, we developed a method for deriving single estimates, rather than a range, of methylation using MS-HRM and compared the values obtained in this way with those obtained using the gold standard quantitative method of pyrosequencing. We derived an interpolation curve using standards of known methylated/ unmethylated ratio (0%, 12.5%, 25%, 50%, 75%, and 100% of methylation) to obtain the best estimate of the extent of methylation for each of our samples. We observed similar profiles of methylation and a high correlation coefficient between the two techniques. Overall, our new approach allows MS-HRM to be used as a quantitative assay which provides results which are comparable with those obtained by pyrosequencing

    Qual è l’effetto della radioterapia sulla funzionalità deglutitoria nei pazienti con tumore del rinofaringe e orofaringe? Risultati a breve termine di uno studio prospettico

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    In questo lavoro vengono riportati i risultati a breve termine di uno studio prospettico, finalizzato alla valutazione strumentale della funzionalità deglutitoria in pazienti affetti da tumore del rinofaringe e orofaringe sottoposti a trattamento radio o radiochemioterapico con tecnica ad intensità modulata (IMRT). L’ IMRT è stata finalizzata, oltre che al miglioramento della conformazione della dose radiante al volume tumorale, alla riduzione della stessa alle strutture responsabili della deglutizione (SWOARs). I criteri dello studio hanno previsto in tutti i pazienti la valutazione strumentale della deglutizione con Videofluoroscopia (VFS), Fibroscopia Endoscopica della deglutizione (FEES) e Scintigrafia Orofaringea (OPES) prima dell’inizio del trattamento e ad 1 mese dal termine dello stesso. Ogni esame è stato eseguito rispettivamente in seguito all’assunzione di un bolo liquido (L) e semiliquido (SL) e per ognuno sono stati calcolati i seguenti valori strumentali: presenza o meno di caduta pre-deglutitoria, presenza o meno di aspirazione, tempo di transito faringeo (PTT) ed indice di ritenzione ipofaringeo (HPRI). Dal Gennaio 2012 al Giugno 2013, un totale di 20 pazienti ha terminato il trattamento ed ha eseguito la valutazione strumentale a 1 mese dal termine della radioterapia. Il confronto tra i valori dell’HPRI prima e dopo il trattamento radiante ha mostrato un peggioramento significativo sia alla FEES-L (p = 0,021) e SL (p = 0,02) che alla VFS-L (p = 0,008) che SL (p = 0,005). Inoltre è stata riscontrata una significativa correlazione tra i valori dell’HPRI basale ed a 1 mese alla FEES-L e SL (p = 0,005) così come alla VFS-L e SL (p 0,2). Solo in pochi pazienti è stata riscontrata la comparsa di caduta pre-deglutitoria ( 1 paziente con tumore della base linguale alla FEES-L e SL) e la presenza di aspirazione (1 paziente con tumore del rinofaringe alla OPES-L e FEES-SL). Nel complesso i risultati iniziali del nostro studio mostrano che l’ IMRT, finalizzata al risparmio delle SWOARs, determina soltanto un significativo incremento della ritenzione di bolo a livello del distretto ipofaringeo. Un follow-up più lungo sarà necessario per valutare se tale incremento sia associato o meno ad un maggior rischio di sviluppare fenomeni di aspirazione tardivi
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