Q-Bounded Maximum Directivity of Self-Resonant Antennas

The upper limit on the directivity of self-resonant antennas that fit within a minimum sphere is determined for a given quality factor. This formulation is obtained by analytically solving a rigorous convex problem and is expressed as a rapidly converging analytical series. The total quality factor, inverse of the relative frequency bandwidth, is formulated by considering the quality factors of individual spherical waves. From the exact series, approximate closed-form formulas have been derived, which exhibit high accuracy in complementary ranges of the minimum circumscribed sphere’s radius. These ranges encompass small antennas as well as intermediate to large antennas. Special emphasis is given to small antennas, where the solution is interpreted as combination of dipolar and quadrupolar Huygens’ source contributions with appropriate closed form coefficients. The solution in this range provides continuity to the maximum directivity between 3 and 8 maintaining a constant Q

Geothermal flux and basal melt rate in the Dome C region inferred from radar reflectivity and heat modelling

Abstract. Basal melt rate is the most important physical quantity to be evaluated when looking for an old-ice drilling site, and it depends to a great extent on the geothermal flux (GF), which is poorly known under the East Antarctic ice sheet. Given that wet bedrock has higher reflectivity than dry bedrock, the wetness of the ice–bed interface can be assessed using radar echoes from the bedrock. But, since basal conditions depend on heat transfer forced by climate but lagged by the thick ice, the basal ice may currently be frozen whereas in the past it was generally melting. For that reason, the risk of bias between present and past conditions has to be evaluated. The objective of this study is to assess which locations in the Dome C area could have been protected from basal melting at any time in the past, which requires evaluating GF. We used an inverse approach to retrieve GF from radar-inferred distribution of wet and dry beds. A 1-D heat model is run over the last 800 ka to constrain the value of GF by assessing a critical ice thickness, i.e. the minimum ice thickness that would allow the present local distribution of basal melting. A regional map of the GF was then inferred over a 80 km  ×  130 km area, with a N–S gradient and with values ranging from 48 to 60 mW m−2. The forward model was then emulated by a polynomial function to compute a time-averaged value of the spatially variable basal melt rate over the region. Three main subregions appear to be free of basal melting, two because of a thin overlying ice and one, north of Dome C, because of a low GF

Il tema degli organismi geneticamente modificati (OGM) fra sapere sapiente e sapere da insegnare. Processo di trasposizione didattica di un insegnamento universitario di ambito agro-ambientale”

The need of investigating academic didactics has been highlightedby many studies (Galliani, 2011; Felisatti, Serbati, 2014). This has beenfurther emphasized by the recent introduction of the academicevaluation system, that ignites the debate on teaching methods(European Commission, 2013).The present research, conducted within the course of “ColtivazioniErbacee” (degree in Management of cultivated plants and landscaping;Department of agricultural and environmental sciences,production, landscape, agroenergy at the University of Milan) duringthe academic year 2015/2016, has the purpose of testing andevaluating teaching methods’ in an academic context. Specificallythe researchers have observed the outcomes in the first phases ofdidactic transposition (Chevallard, 1985), in regard to the acquisitionof inter-disciplinary complex concepts that are characterizedas “socially acute questions”.The researchers have conducted the didactic experimentationwith a double approach (disciplinary and didactic) towards thetransformation of “scholarly knowledge” in “knowledge to betaught” (Chevallard 1985; Develay, 1995; Astolfi, 2008). For this purpose,we have applied an immersive didactic methodology (Nigris,2016; Rossi, 2012), built on the model of philosophical dispute (Nicolli,Cattani, 2006) and embodied simulation (Rossi, 2012; Caracciolo,2014).The methodology chosen, referable to descriptive case study (Yin,2006), has enhanced (according to Merriam 2002) both the use ofdifferent research methods (semi-structured interviews, focusgroups,semi-structured questionnaires) and interpretation perspectivesduring the analysis phases.Triangulation of data (Janesick, 2000) and investigators (Knafl, Breitmayer,1993) enabled the identification and the dual reading – disciplinaryand didactic – of some critical questions of the didactictransposition’s initial stage: the influence of the didactic dispositive(philosophical dispute and embodied simulation) in the constructionof the learning objectives; the connection with theconcept of “socially acute questions” (Legardez, Simonneaux,2006).Numerosi studi, negli ultimi anni, hanno sottolineato la necessità di indagare la qualità della didattica universitaria e dei servizi di sostegno al percorso di formazione offerti agli studenti (Galliani, 2011; Felisatti & Serbati, 2014). Ciò è stato messo in ulteriore risalto dalla recente introduzione del sistema di valutazione universitario, che amplia il dibattito sui metodi di insegnamento (European Commission, 2013).La presente ricerca, svolta nell’ambito del corso di Coltivazioni Erbacee, della laurea triennale di Produzione e Protezione delle piante, del Dipartimento di Scienze agrarie e ambientali dell’Università degli Studi di Milano, durante l’anno accademico 2015/2016, si è posta l’obiettivo di sperimentare e valutare strategie di miglioramento delle modalità di insegnamento accademico. Nello specifico, si sono osservati gli esiti nelle prime fasi del processo di trasposizione didattica (Chevallard, 1985) relativamente all’acquisizione di concetti complessi, di ambito interdisciplinare, che si caratterizzano come questioni “socialmente vive”.Si è scelto di seguire la sperimentazione con un interesse epistemologicodi duplice matrice, disciplinare e didattico, secondo una doppia prospettiva di selezione del sapere sapiente e di trasformazione in sapere da insegnare, definita come esercizio della ‘vigilanza epistemologica’ (Chevallard 1985; Develay, 1995; Astolfi, 2008). A tal fine, si è proposta e applicata una metodologia didattica di tipo immersivo (Nigris, 2016; Rossi, 2012), costruita sul modello della disputa filosofica (Nicolli, Cattani, 2006) e in continuità conle pratiche di simulazione incarnata (Rossi, 2012; Caracciolo, 2014).La metodologia di ricerca adottata, riferibile alla strategia del descriptivecase study (Yin, 2006), ha valorizzato, seguendo Merriam(2002), sia l’utilizzo di strumenti diversificati di documentazione(interviste semi-strutturate, focus-group, questionari semi-strutturati).sia le diverse prospettive interpretative nella fase di analisi.La triangolazione dei metodi di raccolta dati (Janesick, 2000) e deiricercatori (Knafl, Breitmayer, 1993) ha permesso l’individuazionee la duplice lettura – disciplinare e didattica – di alcune questionirilevanti della fase iniziale della trasposizione didattica: l’influenzadel dispositivo didattico (disputa e simulazione incarnata) nellastrutturazione degli obiettivi di apprendimento, relativi all’acquisizionedi concetti complessi; il raccordo con il concetto di ‘questionisocialmente vive’ (Legardez, Simonneaux, 2006)

Microzonazione sismica di un centro abitato di piccole dimensioni: il caso studio di Sant’Agata Fossili (AL)

In questo lavoro sono descritte le attività svolte nell’ambito del Progetto Europeo Strategico RISKNAT riguardanti l’analisi di microzonazione di Sant’Agata Fossili (AL). Sono in particolare descritte tutte le indagini ed analisi numeriche condotte al fine di ottenere una microzonazione sismica di livello 3 secondo quanto previsto nelle recenti linee guida nazionali degli. Al fine inoltre di valutare le ricadute di tipo applicativo di una corretta microzonazione sismica del territorio, sono state realizzate delle simulazioni di scenario adottando come riferimento gli spettri di risposta ottenuti dall’analisi di microzonazione. Le valutazioni di scenario ottenute sono state infine confrontate con le previsioni di scenario realizzabili a priori sulla base dell’adozione degli spettri di risposta definiti nelle Norme Tecniche per le Costruzioni

Allergic diseases in the elderly: biological characteristics and main immunological and non-immunological mechanisms

Life expectancy and the number of elderly people are progressively increasing around the world. Together with other pathologies, allergic diseases also show an increasing incidence in geriatric age. This is partly due to the growing emphasis on a more accurate and careful diagnosis of the molecular mechanisms that do not allow to ignore the real pathogenesis of many symptoms until now unknown, and partly to the fact that the allergic people from 20 years ago represent the elderly population now. Moreover, environmental pollution predisposes to the onset of allergic asthma and dermatitis which are the result of internal pathologies more than the expression of allergic manifestations. At the same time the food contamination permits the onset of allergic diseases related to food allergy. In this review we provide the state of the art on the physiological changes in the elderly responsible for allergic diseases, their biological characteristics and the major immunological and extra immunological mechanisms. Much emphasis is given to the management of several diseases in the elderly, including anaphylactic reactions. Moreover, some new features are discussed, such as management of asthma with the support of physical activity and the use of the AIT as prevention of respiratory diseases and for the purpose of a real and long lasting benefit. The mechanisms of adverse reactions to drugs are also discussed, due to their frequency in this age, especially in polytherapy regimens. Study of the modifications of the immune system is also of great importance, as regards to the distribution of the lymphocytes and also the presence of a chronic inflammatory disease related to the production of cytokines, especially in prevision of all the possible therapies to be adopted to allow an active and healthy agin

Use of Intravenous Immunoglobulin Therapy at Unconventional Doses in Refractory Fulminant Systemic Lupus Erythematosus

The use of human intravenous immunoglobulins (IVIg) in systemic lupus erythematosus (SLE) currently relies on evidence from small case series and is mainly regarded as an off-label strategy in cases that are refractory to conventional therapies or poorly controlled with high doses of corticosteroids. Standard dosage regimens typically entail the administration of a total amount of 2 g/kg of IVIg divided into five consecutive days in order to minimize the risk of severe adverse events. We herein describe the case of a 28-year-old woman with a known history of antiphospholipid syndrome (APS) who was admitted to our hospital following fulminant onset of SLE in spite of ongoing immunosuppressive therapy. Acute renal insufficiency with nephrotic-range proteinuria, central nervous system involvement, severe thrombocytopenia, malar rash, pancreatic injury and moderate-severe aortic valve steno-insufficiency were the most prominent clinical manifestations, along with high titres of anti-dsDNA antibodies. Pulses of methyl-prednisolone followed by high-dose corticosteroids proved ineffective. Strikingly, IVIg therapy delivered at unconventional doses (1.2 g/kg) due to the presence of multiple risk factors for adverse events resulted in a significant, comprehensive clinical improvement. Although large-scale randomized double-blind studies are needed, the use of IVIg might constitute a valuable therapeutic modality as a last-resort strategy in cases of fulminant SLE. The total dose of immunoglobulins should be dictated by the clinical response as well as the presence of pre-existing risk factors for adverse events

Allergic diseases in the elderly: Biological characteristics and main immunological and non-immunological mechanisms

Life expectancy and the number of elderly people are progressively increasing around the world. Together with other pathologies, allergic diseases also show an increasing incidence in geriatric age. This is partly due to the growing emphasis on a more accurate and careful diagnosis of the molecular mechanisms that do not allow to ignore the real pathogenesis of many symptoms until now unknown, and partly to the fact that the allergic people from 20 years ago represent the elderly population now. Moreover, environmental pollution predisposes to the onset of allergic asthma and dermatitis which are the result of internal pathologies more than the expression of allergic manifestations. At the same time the food contamination permits the onset of allergic diseases related to food allergy. In this review we provide the state of the art on the physiological changes in the elderly responsible for allergic diseases, their biological characteristics and the major immunological and extra immunological mechanisms. Much emphasis is given to the management of several diseases in the elderly, including anaphylactic reactions. Moreover, some new features are discussed, such as management of asthma with the support of physical activity and the use of the AIT as prevention of respiratory diseases and for the purpose of a real and long lasting benefit. The mechanisms of adverse reactions to drugs are also discussed, due to their frequency in this age, especially in polytherapy regimens. Study of the modifications of the immune system is also of great importance, as regards to the distribution of the lymphocytes and also the presence of a chronic inflammatory disease related to the production of cytokines, especially in prevision of all the possible therapies to be adopted to allow an active and healthy aging

Allergic diseases in the elderly: Biological characteristics and main immunological and non-immunological mechanisms

Life expectancy and the number of elderly people are progressively increasing around the world. Together with other pathologies, allergic diseases also show an increasing incidence in geriatric age. This is partly due to the growing emphasis on a more accurate and careful diagnosis of the molecular mechanisms that do not allow to ignore the real pathogenesis of many symptoms until now unknown, and partly to the fact that the allergic people from 20 years ago represent the elderly population now. Moreover, environmental pollution predisposes to the onset of allergic asthma and dermatitis which are the result of internal pathologies more than the expression of allergic manifestations. At the same time the food contamination permits the onset of allergic diseases related to food allergy. In this review we provide the state of the art on the physiological changes in the elderly responsible for allergic diseases, their biological characteristics and the major immunological and extra immunological mechanisms. Much emphasis is given to the management of several diseases in the elderly, including anaphylactic reactions. Moreover, some new features are discussed, such as management of asthma with the support of physical activity and the use of the AIT as prevention of respiratory diseases and for the purpose of a real and long lasting benefit. The mechanisms of adverse reactions to drugs are also discussed, due to their frequency in this age, especially in polytherapy regimens. Study of the modifications of the immune system is also of great importance, as regards to the distribution of the lymphocytes and also the presence of a chronic inflammatory disease related to the production of cytokines, especially in prevision of all the possible therapies to be adopted to allow an active and healthy aging

Notulae to the Italian flora of algae, bryophytes, fungi and lichens: 13

In this contribution, new data concerning bryophytes, fungi and lichens of the Italian flora are presented. It includes new records and confirmations for the bryophyte genera Bryum, Cryphaea, Didymodon, and Grimmia; the fungal genera Bryostigma, Cercidospora, Conocybe, Cortinarius, Endococcus, Inocybe, Psathyrella, and Sphaerellothecium; the lichen genera Agonimia, Anisomeridium, Bilimbia, Diplotomma, Gyalecta, Huneckia, Lecidella, Lempholemma, Myriolecis, Nephroma, Pannaria, Pycnothelia, Pyrrhospora, Rinodina, Stereocaulon, Thalloidima, Trapelia, Usnea, Variospora, and Verrucaria

The Fatty Liver Index: a simple and accurate predictor of hepatic steatosis in the general population

BACKGROUND: Fatty liver (FL) is the most frequent liver disease in Western countries. We used data from the Dionysos Nutrition & Liver Study to develop a simple algorithm for the prediction of FL in the general population. METHODS: 216 subjects with and 280 without suspected liver disease were studied. FL was diagnosed by ultrasonography and alcohol intake was assessed using a 7-day diary. Bootstrapped stepwise logistic regression was used to identify potential predictors of FL among 13 variables of interest [gender, age, ethanol intake, alanine transaminase, aspartate transaminase, gamma-glutamyl-transferase (GGT), body mass index (BMI), waist circumference, sum of 4 skinfolds, glucose, insulin, triglycerides, and cholesterol]. Potential predictors were entered into stepwise logistic regression models with the aim of obtaining the most simple and accurate algorithm for the prediction of FL. RESULTS: An algorithm based on BMI, waist circumference, triglycerides and GGT had an accuracy of 0.84 (95%CI 0.81–0.87) in detecting FL. We used this algorithm to develop the "fatty liver index" (FLI), which varies between 0 and 100. A FLI < 30 (negative likelihood ratio = 0.2) rules out and a FLI ≥ 60 (positive likelihood ratio = 4.3) rules in fatty liver. CONCLUSION: FLI is simple to obtain and may help physicians select subjects for liver ultrasonography and intensified lifestyle counseling, and researchers to select patients for epidemiologic studies. Validation of FLI in external populations is needed before it can be employed for these purposes