Pituitary Macroadenoma and Severe Hypothyroidism: The Link between Brain Imaging and Thyroid Function

In case of primary hypothyroidism, reactive pituitary hyperplasia can manifest as pituitary (pseudo) macroadenoma. We report the case of a 12-year-old boy who was evaluated for impaired growth velocity and increased body weight. Because of low insulin-like growth factor 1 levels and poor response to the growth hormone stimulation test, brain magnetic resonance imaging was performed and a pituitary macroadenoma was found. Treatment with levothyroxine was started, and thyroid function was evaluated approximately every 40 days to titrate the dosage. After few months of therapy, the size of the macroadenoma decreased and growth hormone secretion normalized. The pituitary returned to normal size in approximately 5 years. The boy went through puberty spontaneously and reached a normal adult height. In a patient affected by primary hypothyroidism, reactive pituitary hyperplasia can cause growth hormone deficiency; however, growth hormone secretion usually normalizes after starting levothyroxine treatment. Pituitary macroadenoma can be difficult to distinguish from severe pituitary hyperplasia; however, pituitary macroadenomas are rare in childhood, and our clinical case underlines how the hormonal evaluation is essential to achieve a correct diagnosis and prevent unnecessary surgery in a context of pituitary mass

Hilbert's 16th Problem for Quadratic Systems. New Methods Based on a Transformation to the Lienard Equation

Fractionally-quadratic transformations which reduce any two-dimensional quadratic system to the special Lienard equation are introduced. Existence criteria of cycles are obtained

Experimental data and simulations of performance and thermal comfort in a patient room equipped with radiant ceiling panels

Hospitals require the highest energy demands in non-residential buildings. They provide healthcare 24/7/365 and, at the same time, they ensure indoor air quality, thermal comfort and sterility. However, several studies reveal that high indoor temperatures and low relative humidity (RH) are often perceived in patient rooms during the heating season, suggesting an important energy saving potential. Against this background, radiant ceiling panel (RCP) systems result to be one of the most appropriate solutions as they allow to achieve significant energy savings while providing the highest level of thermal and acoustic comfort, as well as of infection control. In the present study the microclimatic survey of a patient room at Maggiore Hospital in Bologna, Italy, equipped with an air conditioning system integrated with RCP, has reported occupant thermal discomfort. Experimental data were used to calibrate a building model and dynamic building energy simulations were carried out to analyse indoor air temperature, relative humidity, predicted mean vote (PMV) and predicted percentage of dissatisfied (PPD) indexes under different inlet air temperatures, to identify the best design conditions for energy efficiency and thermal comfort improvement. It was found that the highest advantages can be obtained when neutral air is supplied

Spin-dependent direct gap emission in tensile-strained Ge films on Si substrates

The circular polarization of direct gap emission of Ge is studied in optically-excited tensile-strained Ge-on-Si heterostructures as a function of doping and temperature. Owing to the spin-dependent optical selection rules, the radiative recombinations involving strain-split light (cG-LH) and heavy hole (cG-HH) bands are unambiguously resolved. The fundamental cG-LH transition is found to have a low temperature circular polarization degree of about 85% despite an off-resonance excitation of more than 300 meV. By photoluminescence (PL) measurements and tight binding calculations we show that this exceptionally high value is due to the peculiar energy dependence of the optically-induced electron spin population. Finally, our observation of the direct gap doublet clarifies that the light hole contribution, previously considered to be negligible, can dominate the room temperature PL even at low tensile strain values of about 0.2%

Beyond variability: Subjective timing and the neurophysiology of motor cognition.

Movement simulation helps increasing the chances to reach goals. A cognitive task used to study the neuro-behavioral aspects of movement simulation is mental rotation: people mentally re-orient rotated pictures of hands. However, the involvement of the primary motor cortex (M1) in mental rotation is largely controversial. Such inconsistency could arise from potential methodological flaws in experimental procedures and data analysis. In particular, until now, the timing of M1 activity has been computed in absolute terms: from the onset of mental rotation (onset-locked), neglecting intra- and inter-subject variability. A novel phase-locked approach is introduced to synchronize the same phases of cognitive processing among different subjects and sessions. This approach was validated in the particular case of corticospinal excitability of the motor cortex during mental rotation. We identified the relative time-windows during which the excitability of M1 is effector-specifically modulated by different features of mental rotation. These time windows correspond to the 55%-85% of the subjective timing. In sum, (i) we introduce a new method to study the neurophysiology of motor cognition, and (ii) validating this method, we shed new light on the involvement of M1 in movement simulation

Molecular Fe, CO and Ni carbide carbonyl clusters and Nanoclusters†

The present minireview highlights the work of our group on Fe, Co and Ni carbide carbonyl clusters and nanoclusters, placing it in the context of the recent literature. After a brief introduction, Section 2 gives a short summary on the general features of molecular carbide carbonyl clusters. Then, specific examples of Fe, Co and Ni carbide carbonyl clusters are presented in the following three Sections. Each Section includes both homometallic and heterometallic clusters, as well as discussion of some of their most relevant chemical, electrochemical, structural and physical properties. General conclusions are outlined in Section 6

Closure theorems for orientor fields and weak convergence

Peer Reviewedhttp://deepblue.lib.umich.edu/bitstream/2027.42/46195/1/205_2004_Article_BF00250438.pd

Towards an integrated model to explain the factors affecting collaborative innovation processes – insights from the agrifood sector

This study explores the relevant factors to involve multiple actors who develop and implement new technologies to build sustainable agrifood systems. By examining 11 cases, we found that technological, organization, environmental, behavioural and interorganizational factors (all mentioned in current literature) as well as collaborative business models (not mentioned in current literature) affect such initiatives. Based on this, we propose an integrated model. The agrifood sector is one of the first sectors in which a collaborative transition unfolds. As other sectors are likely to undergo similar transitions in the near future, lessons learnt from the agrifood sector can guide these transitions

STRATEGIES TO INCREASE WATER PRODUCTIVITY IN IRRIGATED RICE SYSTEMS: IS REDUCING WATER INPUTS THE KEY?

La crescita della domanda mondiale di cibo e l\u2019aumentata incidenza di situazioni di carenza idrica ha notevolmente accentuato l\u2019attenzione sulla risicoltura, data la sua importanza per la nutrizione umana e il suo contributo ai prelievi idrici per fini irrigui. Pi\uf9 del 75% della produzione mondiale di riso ha infatti luogo in risaie irrigate che utilizzano circa il 40% dell\u2019acqua destinata al settore agricolo. Alla luce di questo contesto (descritto nel Capitolo 1), la Tesi si pone l\u2019obiettivo di valutare diverse tecniche di gestione dell\u2019acqua in risaia come risposta alle crescenti pressioni sugli agricoltori che sono chiamati a massimizzare le produzioni, riducendo al contempo i volumi irrigui apportati. Il lavoro \ue8 articolato su tre principali aree di indagine tra loro interconnesse: (i) ruolo delle tecniche di monitoraggio nel favorire l\u2019analisi dei fattori che determinano l\u2019efficienza d\u2019uso dell\u2019acqua; (ii) valutazione di diverse strategie irrigue alla scala di risaia; (iii) studio delle variazioni dei fabbisogni irrigui distrettuali laddove la sommersione tradizionale fosse sostituita da tecniche di risparmio idrico su larga scala. Per quanto concerne il primo punto, l\u2019attivit\ue0 di Tesi ha contribuito allo sviluppo del prototipo di un innovativo sistema per il monitoraggio delle dinamiche dell\u2019acqua in camere di risaia soggette a diverse tecniche irrigue. Svariati sensori sono stati utilizzati in maniera integrata permettendo la misura di diversi processi con alta risoluzione temporale (Capitolo 2). In aggiunta alle tecniche di monitoraggio a terra, \ue8 stata valutata la possibilit\ue0 di impiego di dati da satellite per la valutazione dello sviluppo della vegetazione nel tempo e nello spazio, informazione necessaria per lo studio di processi legati allo sviluppo vegetativo (Capitolo 3). Alla scala di campo sono stati valutati i bilanci idrici e gli indici di uso dell\u2019acqua di tre diverse tecniche di gestione: semina in acqua e sommersione continua (pratica tradizionale), e due tecniche alternative che consistono nella semina interrata e sommersione ritardata e semina interrata e irrigazione intermittente. Se, da un alto, la sommersione ritardata ha determinato riduzioni del raccolto del 3% a fronte di risparmi idrici del 20%, l\u2019irrigazione intermittente ha visto riduzioni del raccolto pari a circa il 30% come contraltare a risparmi idrici dell\u2019ordine del 65%. I valori pi\uf9 alti per quanto riguarda l\u2019indice di produttivit\ue0 dell\u2019acqua sono stati ottenuti con riso irrigato ad intermittenza, tuttavia la sua sostenibilit\ue0 economica sarebbe da valutare attentamente, date le significative perdite di raccolto osservate. Inoltre, \ue8 stata riscontrata una significativa variabilit\ue0 nei fabbisogni irrigui dei trattamenti in sommersione, i quali hanno subito variazioni comprese tra il 40% e il 50% da un anno al successivo (variazione concentrate soprattutto all\u2019inizio della stagione). Prendendo come riferimento la sommersione tradizionale, si \ue8 riscontrato un dimezzamento dei volumi irrigui necessari che sono passati da circa 3000 mm a 1500 mm. Tali variazioni sono state avvalorate da un\u2019analisi statistica e sono state attribuite alla combinazione di diversi fattori quali la profondit\ue0 di falda all\u2019inizio della stagione e modificazioni a livello delle propriet\ue0 e della struttura del suolo. Successivamente, il potenziale risparmio idrico conseguente ad un abbandono della tecnica di sommersione \ue8 stato valutato alla scala di distretto irriguo (Capitolo 5). I fabbisogni irrigui delle diverse colture del distretto (riso sommerso, mais irriguo e pioppo irriguo) sono stati stimati lungo un periodo di 4 anni grazie all\u2019applicazione, in maniera distribuita, del modello idrologico SWAP e all\u2019uso di equazioni di bilancio di massa. Successivamente, \ue8 stata individuata una relazione empirica che lega la soggiacenza alla ricarica di falda (data dall\u2019acqua di percolazione dei campi irrigati). Per lo scenario di conversione a riso irrigato, si \ue8 prestata particolare attenzione al meccanismo di feedback che lega il livello di falda ai volumi irrigui necessari. L\u2019importanza di questo legame \ue8 stata messa in luce attraverso lo sviluppo di due casi di studio. Nel primo caso, il feedback \ue8 stato trascurato e la stima dei fabbisogni irrigui \ue8 fatta sulla base degli attuali livelli di falda. Nel secondo caso invece, la stima devi volumi irrigui necessari \ue8 fatta in funzione dall\u2019equilibrio soggiacenza-ricarica che verrebbe ad instaurarsi a seguito di una consistente variazione delle pratiche irrigue. Nello scenario senza feedback sono state stimate riduzioni dei fabbisogni irrigui dopo una conversione delle tecniche irrigue pari al 65%. Tali riduzioni sono state invece del 45% quando il meccanismo di feedback \ue8 stato considerato nell\u2019analisi. Tuttavia il mantenimento di un turno irriguo per il mais di 15 giorni si \ue8 rivelato non sufficiente per il soddisfacimento dei fabbisogni idrici della coltura a causa dell\u2019aumentata soggiacenza. Accorciare il turno irriguo del mais a 10 giorni ha determinato un\u2019ulteriore riduzione dei risparmi ottenibili con una completa conversione a riso irrigato ad intermittenza (riduzione dei fabbisogni irrigui distrettuali pari al 40%). Oltre ad aspetti strettamente legati ai volumi idrici, sono state inoltre investigate le dinamiche del carbonio organico disciolto in funzione delle diverse tecniche di gestione dell\u2019acqua (Capitolo 6). Lo studio ha evidenziato un legame molto forte tra il ciclo del carbonio organico disciolto e le condizioni riducenti indotte dalla continua saturazione del suolo. Infine \ue8 stato sviluppato un caso di studio per quantificare il ruolo della falda nella riduzione dei fabbisogni irrigui di colture irrigate ad intermittenza come il mais. I risultati hanno evidenziato un contributo della risalita capillare pari a circa il 50% del volume evapotraspirato dalla coltura in aree con bassa soggicanza di falda (Capitolo 7). In conclusione, nonostante la tendenza a voler proporre soluzioni di carattere generale al problema dell\u2019efficienza d\u2019uso dell\u2019acqua in agricoltura, le attivit\ue0 di ricerca proposte nella seguente Tesi hanno messo in luce come sia difficile stabilire se il risparmio idrico sia effettivamente un obiettivo da perseguire in qualsiasi contesto produttivo (Capitolo 8).In a context of increasing food demand and increasing risk of water scarcity, irrigated rice systems are receiving a specific attention because of the role of rice in food nutrition and because of the relevant share of water withdrawals required by rice farming. More than 75% of the global rice supply is in fact produced in lowland irrigated areas, which in turn require around 40% of the global water used for irrigation. Given this background (Chapter 1), the Thesis investigates the role of water management in irrigated rice system, in response to the compelling pressures on farmers to maximise crop production while reducing the amount of water used for irrigation purposes. Three interlinked focus areas have been evaluated: (i) the role of monitoring techniques in improving knowledge on processes driving water use in rice systems, (ii) field-scale evaluation of the performance of different water regimes, (iii) effects induced by a large adoption of water saving technologies on the irrigation requirements at the district scale. First, a prototype of an innovative integrated multi-sensor system was developed in order to monitor water dynamics in paddy fields under different water regimes. Several monitoring devices were effectively used in an combined way, enabling to measure different processes with a high temporal resolution (Chapter 2). In addition to on-ground devices, the opportunity offered by the use of remote sensed data to capture the spatio-temporal evolution of crop growth and study crop-related processes was investigated (Chapter 3). Focussing on the field scale (Chapter 4), water balances and water use indices of three rice water managements were compared: water seeding-continuous flooding (\u201ctraditional\u201d practice) and two alternative regimes being dry seeding-delayed flooding and dry seeding-intermittent irrigation. If delayed flooding determined average yield reductions by 3% against a decrease of water applications by 20%, the 65% reduction of water applications in intermittent irrigated rice was counterbalanced by yield losses close to 30%. Therefore, in spite of intermittent irrigation achieving the highest water productivity, the economic practicality of the method could be questioned. Moreover, the irrigation requirements of the flooded treatments were found to vary significantly between years, with variations by 40% to 50% (mostly occurred in the first part of the season). Taking as a reference the traditional flooding regime, irrigation requirements halved from 3,000 mm in the first season to 1,500 mm in the subsequent one. Variations were statically validated and they were attributed to a combination of abiotic and biotic factors including groundwater levels at the beginning of the season and soil-related aspects. Then, the extent of reductions in irrigation requirements when replacing traditional flooding with intermittent irrigation was investigated at the scale of an irrigation district (Chapter 5). Water requirements of the different crops (flooded rice, irrigated maize and irrigated poplars) were investigated over a 4-year period by the application of a distributed modelling approach (use of the SWAP model) and water balance equations. An empirical relationship between groundwater recharge (provided by percolation from irrigated fields) and the groundwater levels was thus identified. For the scenario of intermittent irrigated rice, a particular attention was paid to the role of the feedback between groundwater levels and irrigation applications. The importance of feedback effects was highlighted by developing a case study where groundwater is assumed invariant from the present state (no feedback) and a case study where the estimated irrigation requirements are congruent with the \u201cnew\u201d equilibrium state between groundwater levels and groundwater recharge. According to the estimates of the scenarios, irrigation withdrawals of the district decreased by around 65% when the feedback mechanism was neglected, while a reduction by 45% was observed when the feedback was accounted for. However, maintaining a 15-days turn for maize irrigation, like in the present state, was found to be inadequate for the full satisfaction of maize water requirements due to the decrease in the groundwater levels. Shortening the irrigation turn of maize to 10 days instead of 15 further decreased the estimate of the savings achievable with flush irrigated rice (reduction of irrigation requirements equal to 40%). In addition to implications on water balance terms, a specific attention was paid on the dynamics of dissolved organic carbon in relation to the water regime. Results of the study highlighted a strong link between the cycling of dissolved organic carbon and the reducing soil conditions resulting from field flooding (Chapter 6). Finally, the role of shallow groundwater table on the reduction of the irrigation requirements of lowland crops under intermittent irrigation was quantified via modelling simulations. Results showed a contribution of capillary rise up to 50% of the amount of water evapotranspirated by the crop (Chapter 7). In spite of the tendency to seek for general and global solutions, the research activities presented in the Thesis highlighted the difficulty to provide a univocal response to the question as to whether reductions of water consumptions in rice paddies should really represent the target to be reached regardless the specific context (Chapter 8)