L’ambiente carsico e l’idrogeologia dei gessi di Sassalbo (MS)

Nel Canale dell’Acqua Torbida (Alta Lunigiana), si trova il maggiore affioramento di evaporiti triassiche della Toscana. Rispetto ai gessi dell’Alta val Secchia (RE), di cui sono il lembo meridionale, appaiono molto meno tettonizzati. L’area carsica, che comprende in prevalenza calcari cavernosi, ha una superficie complessiva di circa 2,2 km2 in cui sono ben rappresentate forme carsiche superficiali, sia macro che micro. Anche i fenomeni carsici sotterranei sembrano essere ben sviluppati: la loro genesi è stata attribuita a periodi di avanzata e arretramento dei ghiacciai durante l’ultimo glaciale. Attualmente nel catasto toscano sono registrate 5 cavità, di cui 4 rilevate. Nell’ambito del Progetto Trias II (studio interdisciplinare svolto dalla Società Speleologica Italiana per conto del Parco Nazionale dell’Appennino Tosco-Emiliano) è stato possibile studiare l’area dal punto di vista morfologico, speleologico e idrochimico, monitorando in continuo alcune delle principali risorgenti carsiche parallelamente ai torrenti cui esse potevano risultare connesse. Nel presente lavoro, dopo breve illustrazione delle morfologie epigee ed ipogee, vengono presentati i risultati del monitoraggio idrologico. Le analisi hanno permesso di evidenziare come in molti casi le acque del carso di Sassalbo siano chimicamente molto simili a quelle del sistema ad ansa ipogea del Tanone della Gacciolina in Alta val di Secchia. Fanno eccezione altre sorgenti, alimentate quasi esclusivamente dalla serie marnoso arenacea e dal macigno, che presentano comportamenti idrodinamici differenti in funzione dei loro specifici bacini di alimentazione.Karst and hydrology of the Sassalbo Gypsa (Massa Carrara – Italy) The largest triassic evaporitic outcrop of Tuscany is located inside the Acqua Torbida creek (Upper Lunigiana). They represent the southernmost and less tectonized part of the Upper Secchia Gypsa (RE). The karst area (some 2,2) consists mostly of limestone (Calcari Cavernosi) with well developed macro – and micro – forms. The underground phenomena are mainly related to the mouventes of glacial tongues during the last Glacial. 5 cavities are presently known and inserted in the Tuscany Cadaster, 4 of which mapped. In the framework of the Trias II Project (an interdisciplinary study sponsored by the Appennino Tosco-Emiliano National Park and performed by the Italian Speleological Society) this area has been investigated from the morphological, speleological, hydrochemical point of view while some of the major springs and related rivers were monitored. In the paper after a short description of the epigean and hypogean forms, the achieved result during the hydrological study are presented. This study evidenced that in many occurrences the behavior of the Sassalbo karst waters is very similar to that of the Tanone della Gacciolina cave in the Upper Secchia Valley. Only a few springs exhibit a different behavior being rather completely fed by the marnoso-arenacea and macigno formations

Superimposé: a 3D structural superposition server

The Superimposé webserver performs structural similarity searches with a preference towards 3D structure-based methods. Similarities can be detected between small molecules (e.g. drugs), parts of large structures (e.g. binding sites of proteins) and entire proteins. For this purpose, a number of algorithms were implemented and various databases are provided. Superimposé assists the user regarding the selection of a suitable combination of algorithm and database. After the computation on our server infrastructure, a visual assessment of the results is provided. The structure-based in silico screening for similar drug-like compounds enables the detection of scaffold-hoppers with putatively similar effects. The possibility to find similar binding sites can be of special interest in the functional analysis of proteins. The search for structurally similar proteins allows the detection of similar folds with different backbone topology. The Superimposé server is available at: http://bioinformatics.charite.de/superimpose

Cost Effectiveness of Data Flow Machines and Vector Processors

Proponents of data flow machines always emphasize the high potential for parallelization and the high performance on numerical applications reachable by that kind of architecture. On the other hand opponents critisize the additional overhead during run time and the difficulties of the memory management. In order to evaluate the cost effectiveness of dynamical data flow machines we compare a well known representative, the Monsoon designed at the MIT, with two vector processors, the Cray I and the Spark 2.0. This comparison is based on a theoretical model, which provides measures for the run time and the cost of the machines. As numerical workload we have chosen some kernels from the Livermore Loops benchmark. In this paper we briefly review the evaluation model, we describe the machines under consideration and finally we present our results of the comparison

The SB-PRAM: Concept, Design and Construction

We summarize the project at the Computer Science Department at the University of Saarbrücken that aims at building the parallel computer SB-PRAM, a scalable shared-memory multi-processor machine based on a modified Fluent Machine [25]. We present the concept of the architecture, highlight some of the design decisions, and describe in some detail the construction of both hardware and software modules

Isolating the Reasons for the Performance of Parallel Machines on Numerical Programs

In this paper we present a nontrivial set of modules which measure performance parameters of node processors and interconnection networks. With the help of these parameters we explain the run time of the following algorithms conjugate gradient method, one--dimensional partial differential equation solver and two-dimensional partial differential equation solver on the parallel machine Ncube-2. The iPSC/860 Hypercube and the vector machine VP100 are analysed in an other paper (see [3]). Our explanations are sometimes within 0.5 % and almost always within 5 % of the measured run times

The SPARK 2.0 system - a special purpose vector processor with a VectorPASCAL compiler

This paper describes the architecture of the Spark 2.0 processor and introduces a compiler for VectorPascal. Features of the architecture are the flexible address generation during vector operations and the large memories closely connected to the functional units. The source language allows to write programs with vector statements avoiding scalar inner loops. The compiler employs several optimizing strategies to utilize the architectural benefits efficiently. 1 Introduction In the scientific world exist many applications (e. g. molecular dynamics [17]) with extensive use of index table driven algorithms. The computational power often required by such applications can only be achieved by parallel systems with powerful node processors. The Spark 2.0 processor reaches a very high sustained /peak performance ratio on index addressed vector operations and seems to be a good candidate for a node (The sustained/peak performance ratio on our molecular dynamics simulation program is five time..

Transient knockdown of tyrosine hydroxylase during development has persistent effects on behaviour in adult zebrafish (Danio rerio)

Abnormal dopamine (DA) signaling is often suggested as causative in schizophrenia. The other prominent hypothesis for this disorder, largely driven by epidemiological data, is that certain adverse events during the early stages of brain development increase an individual's risk of developing schizophrenia later in life. However, the clinical and preclinical literature consistently implicates behavioural, cognitive, and pharmacological abnormalities, implying that DA signaling is abnormal in the adult brain. How can we reconcile these two major hypotheses underlying much of the clinical and basic research into schizophrenia? In this study we have transiently knocked down tyrosine hydroxylase (TH, the rate limiting enzyme in DA synthesis) gene expression in the early stages of brain development in zebrafish using morpholinos. We show that by adulthood, TH and DA levels have returned to normal and basic DA-mediated behaviours, such as locomotion, are also normal. However, when they were exposed to a novel environment the levels of freezing and immediate positioning in deeper zones were significantly reduced in these adult fish. The neurochemistry underlying these behaviours is complex, and the exact mechanisms for these abnormal behaviours remains unknown. This study demonstrates that early transient alterations in DA ontogeny can produce persistent alterations in adult brain function and suggests that the zebrafish may be a promising model animal for future studies directed at clarifying the basic neurodevelopmental mechanisms behind complex psychiatric disease

Efficiency of <i>th1</i> gene knock down at 27 hpf.

<p>RNA expression levels of zebrafish <i>th1</i> transcripts are presented as a percentage relative to the expression of the zebrafish housekeeping gene <i>elf1a</i>. [F2,8 = 4.9 p<0.05] Values are mean±SEM. * p<0.05.</p

The open field, place preference and the novel diving tank.

<p>Illustration of the open-field tank (A), place preference (B), and the novel diving test tank (C) with specific dimensions. Virtual divisions in the open-field tank and in four zones of the diving tank (Z1/top – Z4/bottom) were used to evaluate fish positioning.</p