Do you see what I mean?

Visualizers, like logicians, have long been concerned with meaning. Generalizing from MacEachren's overview of cartography, visualizers have to think about how people extract meaning from pictures (psychophysics), what people understand from a picture (cognition), how pictures are imbued with meaning (semiotics), and how in some cases that meaning arises within a social and/or cultural context. If we think of the communication acts carried out in the visualization process further levels of meaning are suggested. Visualization begins when someone has data that they wish to explore and interpret; the data are encoded as input to a visualization system, which may in its turn interact with other systems to produce a representation. This is communicated back to the user(s), who have to assess this against their goals and knowledge, possibly leading to further cycles of activity. Each phase of this process involves communication between two parties. For this to succeed, those parties must share a common language with an agreed meaning. We offer the following three steps, in increasing order of formality: terminology (jargon), taxonomy (vocabulary), and ontology. Our argument in this article is that it's time to begin synthesizing the fragments and views into a level 3 model, an ontology of visualization. We also address why this should happen, what is already in place, how such an ontology might be constructed, and why now

Modeling of the Acute Toxicity of Benzene Derivatives by Complementary QSAR Methods

A data set containing acute toxicity values (96-h LC50) of 69 substituted benzenes for fathead minnow (Pimephales promelas) was investigated with two Quantitative Structure- Activity Relationship (QSAR) models, either using or not using molecular descriptors, respectively. Recursive Neural Networks (RNN) derive a QSAR by direct treatment of the molecular structure, described through an appropriate graphical tool (variable-size labeled rooted ordered trees) by defining suitable representation rules. The input trees are encoded by an adaptive process able to learn, by tuning its free parameters, from a given set of structureactivity training examples. Owing to the use of a flexible encoding approach, the model is target invariant and does not need a priori definition of molecular descriptors. The results obtained in this study were analyzed together with those of a model based on molecular descriptors, i.e. a Multiple Linear Regression (MLR) model using CROatian MultiRegression selection of descriptors (CROMRsel). The comparison revealed interesting similarities that could lead to the development of a combined approach, exploiting the complementary characteristics of the two approaches

The evaluation of an active networking approach for supporting the QOS requirements of distributed virtual environments

This paper describes work that is part of a more general investigation into how Active Network ideas might benefit large scale Distributed-Virtual-Environments (DVEs). Active Network approaches have been shown to offer improved solutions to the Scalable Reliable Multicast problem, and this is in a sense the lowest level at which Active Networks might benefit DVEs in supporting the peer-to-peer architectures considered most promising for large scale DVEs. To go further than this, the key benefit of Active Networking is the ability to take away from the application the need to understand the network topology and delegate the execution of certain actions, for example intelligent message pruning, to the network itself. The need to exchange geometrical information results in a type of traffic that can place occasional, short-lived, but heavy loads on the network. However, the Level of Detail (LoD) concept provides the potential to reduce this loading in certain circumstances. This paper introduces the performance modelling approach being used to evaluate the effectiveness of active network approaches for supporting DVEs and presents an evaluation of messages filtering mechanisms, which are based on the (LoD) concept. It describes the simulation experiment used to carry out the evaluation, presents its results and discusses plans for future work

Il ruolo della PET/TC con 18F-DOPA nella diagnosi e nel follow-up dei paragangliomi surrenalici ed extra-surrenalici

I paragangliomi (PGL) sono dei rari tumori che originano da agglomerati di cellule neuroendocrine, detti paragangli, connessi al sistema nervoso simpatico e parasimpatico, che si caratterizzano per la capacità di produrre, metabolizzare, immagazzinare e secernere catecolamine. I PGL del simpatico originano dalla midollare del surrene (feocromocitomi) o dai gangli simpatici dell’addome e del torace e si caratterizzano per l’ipersecrezione di catecolamine. I PGL del parasimpatico si localizzano invece a livello del distretto testa-collo (HNPGL) e secernono catecolamine solo in una minoranza dei casi. La presentazione clinica è eterogenea con sintomi correlati all’ipersecrezione di catecolamine per i PGL simpatici, mentre gli HNPGL possono essere asintomatici o determinare disturbi da effetto massa. Si tratta di neoplasie a lento accrescimento e tendenzialmente benigne che possono presentarsi in forma sporadica o associate a sindromi ereditarie, con età di insorgenza variabile e senza prevalenza di sesso. La diagnosi di questi tumori si basa su indagini biochimiche (dosaggio di catecolamine e/o loro metaboliti nel plasma e nelle urine), morfologiche (TC e RM) e funzionali (scintigrafia e PET). Scopo dello studio: l’obiettivo di questo studio è stato quello di valutare l’utilità clinica della PET/TC con 18F-DOPA nei pazienti con PGL surrenalici ed extra-surrenalici. Materiali e metodi: ventisei pazienti consecutivi con sospetto PGL o recidiva di PGL sono stati studiati con RM (e/o TC) e con 18F-DOPA PET/TC. La conferma istologica è stata ottenuta in venti casi. In tredici pazienti è stato eseguito lo studio delle mutazioni per i geni di suscettibilità del PGL (VHL, RET, SDHx, TMEM127). Risultati: quattordici pazienti sono risultati affetti da PGL (8 HNPGL, 1 PGL toracico e 5 PGL addominali), nei restanti 12 pazienti sono state riscontrate formazioni di altra natura. Dei tredici pazienti in cui è stata effettuata l’analisi genetica, tre presentavano mutazioni del gene SDHD, due del gene SDHC, uno del gene SDHB e uno del gene TMEM. La 18F-DOPA PET/TC ha evidenziato una patologica captazione del tracciante in tredici pazienti su ventisei, riuscendo ad identificare tutti i PGL, ad eccezione di un paziente con metastasi ossee da pregresso feocromocitoma maligno. Nei pazienti non affetti da PGL non è stata riscontrata alcuna captazione patologica di 18F-DOPA. Nella popolazione complessiva, la 18F-DOPA PET/TC ha mostrato una sensibilità del 92.8%, una specificità del 100%, un valore predittivo positivo e negativo rispettivamente del 100% e del 92.3% e un’accuratezza diagnostica del 96.2%. Nel sottogruppo di pazienti con sospetto PGL del collo/torace, la sensibilità, la specificità, il valore predittivo positivo e negativo e l’accuratezza diagnostica sono risultate del 100%. Nel sottogruppo di pazienti con sospetto PGL addominale la sensibilità è stata dell’80%, la specificità del 100%, il valore predittivo positivo e negativo rispettivamente del 100% e del 91.7% e l’accuratezza diagnostica del 93.7%. Conclusioni: questo studio conferma che la 18F-DOPA PET/TC è uno strumento diagnostico importante per l’identificazione dei PGL, in particolare per quelli localizzati nel distretto testa/collo, indipendentemente dall’assetto genetico

Anthelmintic action of plant cysteine proteinases against the rodent stomach nematode, Protospirura muricola, in vitro and in vivo

Cysteine proteinases from the fruit and latex of plants, including papaya, pineapple and fig, were previously shown to have a rapid detrimental effect, in vitro, against the rodent gastrointestinal nematodes, H eligmosomoides polygyrus (which is found in the anterior small intestine) and Trichuris miti,is (which resides in the caecum). Proteinases in the crude latex of papaya also showed anthelmintic efficacy against both nematodes in vivo. In this paper, we describe the in vitro and in vivo effects of these plant extracts against the rodent nematode, Protospirua muricola, which is found in the stomach. As in earlier work, all the plant cysteine proteinases examined, with the exception of actinidain from the juice of kiwi fruit, caused rapid loss of motility and digestion of the cuticle, leading to death of the nematode in vitro. In vivo, in contrast to the efficacy against H. polygyrus and T. muris, papaya latex only showed efficacy against P. muricola adult female worms when the stomach acidity had been neutralized prior to administration of papaya latex. Therefore, collectively, our studies have demonstrated that, with the appropriate formulation, plant cysteine proteinases have efficacy against nematodes residing throughout the rodent gastrointestinal tract