Meta-models, environment and layers: agent-oriented engineering of complex systems

Traditional software engineering approaches and metaphors fall short when applied to areas of growing relevance such as electronic commerce, enterprise resource planning, and mobile computing: such areas, in fact, generally call for open architectures that may evolve dynamically over time so as to accommodate new components and meet new requirements. This is probably one of the main reasons that the agent metaphor and the agent-oriented paradigm are gaining momentum in these areas. This thesis deals with the engineering of complex software systems in terms of the agent paradigm. This paradigm is based on the notions of agent and systems of interacting agents as fundamental abstractions for designing, developing and managing at runtime typically distributed software systems. However, today the engineer often works with technologies that do not support the abstractions used in the design of the systems. For this reason the research on methodologies becomes the basic point in the scientific activity. Currently most agent-oriented methodologies are supported by small teams of academic researchers, and as a result, most of them are in an early stage and still in the first context of mostly \academic" approaches for agent-oriented systems development. Moreover, such methodologies are not well documented and very often defined and presented only by focusing on specific aspects of the methodology. The role played by meta- models becomes fundamental for comparing and evaluating the methodologies. In fact a meta-model specifies the concepts, rules and relationships used to define methodologies. Although it is possible to describe a methodology without an explicit meta-model, formalising the underpinning ideas of the methodology in question is valuable when checking its consistency or planning extensions or modifications. A good meta-model must address all the different aspects of a methodology, i.e. the process to be followed, the work products to be generated and those responsible for making all this happen. In turn, specifying the work products that must be developed implies dening the basic modelling building blocks from which they are built. As a building block, the agent abstraction alone is not enough to fully model all the aspects related to multi-agent systems in a natural way. In particular, different perspectives exist on the role that environment plays within agent systems: however, it is clear at least that all non-agent elements of a multi-agent system are typically considered to be part of the multi-agent system environment. The key role of environment as a first-class abstraction in the engineering of multi-agent system is today generally acknowledged in the multi-agent system community, so environment should be explicitly accounted for in the engineering of multi-agent system, working as a new design dimension for agent-oriented methodologies. At least two main ingredients shape the environment: environment abstractions - entities of the environment encapsulating some functions -, and topology abstractions - entities of environment that represent the (either logical or physical) spatial structure. In addition, the engineering of non-trivial multi-agent systems requires principles and mechanisms for supporting the management of the system representation complexity. These principles lead to the adoption of a multi-layered description, which could be used by designers to provide different levels of abstraction over multi-agent systems. The research in these fields has lead to the formulation of a new version of the SODA methodology where environment abstractions and layering principles are exploited for en- gineering multi-agent systems.

Biofilms on exposed monumental stones: mechanism of formation and development of new control methods

Within the stone monumental artefacts artistic fountains are extremely favorable to formation of biofilms, giving rise to biodegradation processes related with physical-chemical and visual aspect alterations, because of their particular exposure conditions. Microbial diversity of five fountains (two from Spain and three from Italy) was investigated. It was observed an ample similarity between the biodiversity of monumental stones reported in literature and that one found in studied fountains. Mechanical procedures and toxic chemical products are usually employed to remove such phototrophic patinas. Alternative methods based on natural antifouling substances are recently experimented in the marine sector, due to their very low environmental impact and for the bio settlement prevention on partially immersed structures of ships. In the present work groups of antibiofouling agents (ABAs) were selected from literature for their ability to interfere, at molecular level, with the microbial communication system “quorum sensing”, inhibiting the initial phase of biofilm formation. The efficacy of some natural antibiofoulants agents (ABAs) with terrestrial (Capsaicine - CS, Cinnamaldehyde - CI) and marine origin (Zosteric Acid - ZA, poly-Alkyl Pyridinium Salts – pAPS and Ceramium botryocarpum extract - CBE), incorporated into two commercial coatings (Silres BS OH 100 - S and Wacker Silres BS 290 - W) commonly used in stone conservation procedures were evaluated. The formation of phototrophic biofilms in laboratory conditions (on Carrara marble specimens and Sierra Elvira stone) and on two monumental fountains (Tacca’s Fountain 2 - Florence, Italy and Fountain from Patio de la Lindaraja - Alhambra Palace, Granada, Spain) has been investigated in the presence or absence of these natural antifouling agents. The natural antibiofouling agents, at tested concentrations, demonstrated a certain inhibitory effect. The silane-siloxane based silicone coating (W) mixing with ABAs was more suitable with respect to ethyl silicate coating (S) and proved efficacy against biofilm formation only when incompletely cured. The laboratory results indicated a positive action in inhibiting the patina formation, especially for poly-alkyl pyridinium salts, zosteric acid and cinnamaldehyde, while on site tests revealed a good effect for zosteric acid.

Untersuchungen über Wechselwirkungen zwischen Proteinen der Leber und dem großen Hüllprotein des Hepatitis-B-Virus

Zusammenfassung:Im Infektionszyklus des Hepatitis-B-Virus spielt das große L-Hüllprotein mit seiner einzigartigen PräS1-Domäne eine zentrale Rolle. Es vermittelt die Bindung und Aufnahme in die Leberzelle, die Verpackung der Nukleokapside in die Virushülle, die Regulation der cccDNA-Amplifikation und eine transkriptionelle Aktivierung in der Wirtszelle. Zur Erfüllung seiner vielfältigen Aufgaben benötigt das L-Protein Unterstützung durch Wirtzellfaktoren, von denen einige im Rahmen dieser Untersuchung durch Verwendung von PräS1-Konstrukten als Fängerproteine im Hefe-Zwei-Hybrid-System identifiziert wurden. Mehrere Klone, die im Hefe-Zwei-Hybrid-Test mit dem C-terminalen PräS1-Fängerprotein (Aminosäure 44-108) isoliert worden waren, enthielten Teile der cDNA von gamma2-Adaptin, einem mutmaßlichen Mitglied der Clathrin-Adaptor-Proteine. Diese sind für intrazelluläre Membrantransportprozesse mittels clathrinumhüllter Vesikel verantwortlich. Unter den interagierenden Klonen, die mit dem N-terminalen Konstrukt des L-Proteins (Aminosäure 1-70) isoliert worden waren, befand sich überproportional häufig eine cDNA, die der schweren Kette H4 der Inter-Alpha-Trypsin-Inhibitor-Familie homolog war. H4 besitzt vermutlich bei der 'Akute-Phase-Reaktion', die Entzündungen folgt, und bei der Stabilisierung der extrazellulären Matrix physiologische Bedeutung. Weitere Klone kodierten für die Serinprotease C1r. Diese ist Bestandteil des C1-Komplex, der ersten Komponente des klassischen Komplementsystems. Die Spezifität der Bindung zwischen den positiven Klonen und der PräS1-Domäne wurde in weiteren biochemischen Interaktionstests bestätigt, sodaß H4, C1r und gamma2-Adaptin als Wirtszellfaktoren in der Physiologie des Hepatitis-B-Virus wahrscheinlich eine Rolle spielen.Abstract:Little is known about host cell factors necessary for hepatitis B virus assembly and infectivity. Central to virogenesis is the large L envelope protein that mediates hepatocyte receptor binding, envelopment of viral capsids, regulation of supercoiled DNA amplification and transcriptional transactivation. To assess its multiple functions and host-protein assistance involved, we here initiated a yeast two-hybrid screen using the L-specific preS1 domain as bait to screen a human liver cDNA library for L-interacting proteins. One of the most prominent cDNAs interacting with aminoacid sequence 44-108 of L-protein encodes for gamma2-adaptin, a novel clathrin adaptor-related protein responsible for protein sorting and trafficking. Among the clones interacting with the N-terminal construct of L-protein (aminoacid sequence 1-70), a frequently isolated cDNA corresponds to the gene for inter-alpha-trypsin family heavy chain H4, likely to be involved in acute inflammatory phase response and stabilization of extracellular matrices. Some other interacting clones were found to carry the cDNA for the serine protease C1r, a subunit of the C1 complex which initiates the classical complement cascade. The specificity of the interaction between the positive clones and the preS1 domain was further confirmed in independent biochemical experiments. Taken together, the results suggest a role for H4, C1r and gamma2-adaptin as host-cell factors in L-mediated process of viral biogenesis and/or pathogenesis.

Architectures and design patterns for functional design of logic control and diagnostics in industrial automation

Recently in most of the industrial automation process an ever increasing degree of automation has been observed. This increasing is motivated by the higher requirement of systems with great performance in terms of quality of products/services generated, productivity, efficiency and low costs in the design, realization and maintenance. This trend in the growth of complex automation systems is rapidly spreading over automated manufacturing systems (AMS), where the integration of the mechanical and electronic technology, typical of the Mechatronics, is merging with other technologies such as Informatics and the communication networks. An AMS is a very complex system that can be thought constituted by a set of flexible working stations, one or more transportation systems. To understand how this machine are important in our society let considerate that every day most of us use bottles of water or soda, buy product in box like food or cigarets and so on. Another important consideration from its complexity derive from the fact that the the consortium of machine producers has estimated around 350 types of manufacturing machine. A large number of manufacturing machine industry are presented in Italy and notably packaging machine industry,in particular a great concentration of this kind of industry is located in Bologna area; for this reason the Bologna area is called “packaging valley”. Usually, the various parts of the AMS interact among them in a concurrent and asynchronous way, and coordinate the parts of the machine to obtain a desiderated overall behaviour is an hard task. Often, this is the case in large scale systems, organized in a modular and distributed manner. Even if the success of a modern AMS from a functional and behavioural point of view is still to attribute to the design choices operated in the definition of the mechanical structure and electrical electronic architecture, the system that governs the control of the plant is becoming crucial, because of the large number of duties associated to it. Apart from the activity inherent to the automation of themachine cycles, the supervisory system is called to perform other main functions such as: emulating the behaviour of traditional mechanical members thus allowing a drastic constructive simplification of the machine and a crucial functional flexibility; dynamically adapting the control strategies according to the different productive needs and to the different operational scenarios; obtaining a high quality of the final product through the verification of the correctness of the processing; addressing the operator devoted to themachine to promptly and carefully take the actions devoted to establish or restore the optimal operating conditions; managing in real time information on diagnostics, as a support of the maintenance operations of the machine. The kind of facilities that designers can directly find on themarket, in terms of software component libraries provides in fact an adequate support as regard the implementation of either top-level or bottom-level functionalities, typically pertaining to the domains of user-friendly HMIs, closed-loop regulation and motion control, fieldbus-based interconnection of remote smart devices. What is still lacking is a reference framework comprising a comprehensive set of highly reusable logic control components that, focussing on the cross-cutting functionalities characterizing the automation domain, may help the designers in the process of modelling and structuring their applications according to the specific needs. Historically, the design and verification process for complex automated industrial systems is performed in empirical way, without a clear distinction between functional and technological-implementation concepts and without a systematic method to organically deal with the complete system. Traditionally, in the field of analog and digital control design and verification through formal and simulation tools have been adopted since a long time ago, at least for multivariable and/or nonlinear controllers for complex time-driven dynamics as in the fields of vehicles, aircrafts, robots, electric drives and complex power electronics equipments. Moving to the field of logic control, typical for industrial manufacturing automation, the design and verification process is approached in a completely different way, usually very “unstructured”. No clear distinction between functions and implementations, between functional architectures and technological architectures and platforms is considered. Probably this difference is due to the different “dynamical framework”of logic control with respect to analog/digital control. As a matter of facts, in logic control discrete-events dynamics replace time-driven dynamics; hence most of the formal and mathematical tools of analog/digital control cannot be directly migrated to logic control to enlighten the distinction between functions and implementations. In addition, in the common view of application technicians, logic control design is strictly connected to the adopted implementation technology (relays in the past, software nowadays), leading again to a deep confusion among functional view and technological view. In Industrial automation software engineering, concepts as modularity, encapsulation, composability and reusability are strongly emphasized and profitably realized in the so-calledobject-oriented methodologies. Industrial automation is receiving lately this approach, as testified by some IEC standards IEC 611313, IEC 61499 which have been considered in commercial products only recently. On the other hand, in the scientific and technical literature many contributions have been already proposed to establish a suitable modelling framework for industrial automation. During last years it was possible to note a considerable growth in the exploitation of innovative concepts and technologies from ICT world in industrial automation systems. For what concerns the logic control design, Model Based Design (MBD) is being imported in industrial automation from software engineering field. Another key-point in industrial automated systems is the growth of requirements in terms of availability, reliability and safety for technological systems. In other words, the control system should not only deal with the nominal behaviour, but should also deal with other important duties, such as diagnosis and faults isolations, recovery and safety management. Indeed, together with high performance, in complex systems fault occurrences increase. This is a consequence of the fact that, as it typically occurs in reliable mechatronic systems, in complex systems such as AMS, together with reliable mechanical elements, an increasing number of electronic devices are also present, that are more vulnerable by their own nature. The diagnosis problem and the faults isolation in a generic dynamical system consists in the design of an elaboration unit that, appropriately processing the inputs and outputs of the dynamical system, is also capable of detecting incipient faults on the plant devices, reconfiguring the control system so as to guarantee satisfactory performance. The designer should be able to formally verify the product, certifying that, in its final implementation, it will perform itsrequired function guarantying the desired level of reliability and safety; the next step is that of preventing faults and eventually reconfiguring the control system so that faults are tolerated. On this topic an important improvement to formal verification of logic control, fault diagnosis and fault tolerant control results derive from Discrete Event Systems theory. The aimof this work is to define a design pattern and a control architecture to help the designer of control logic in industrial automated systems. The work starts with a brief discussion on main characteristics and description of industrial automated systems on Chapter 1. In Chapter 2 a survey on the state of the software engineering paradigm applied to industrial automation is discussed. Chapter 3 presentes a architecture for industrial automated systems based on the new concept of Generalized Actuator showing its benefits, while in Chapter 4 this architecture is refined using a novel entity, the Generalized Device in order to have a better reusability and modularity of the control logic. In Chapter 5 a new approach will be present based on Discrete Event Systems for the problemof software formal verification and an active fault tolerant control architecture using online diagnostic. Finally conclusive remarks and some ideas on new directions to explore are given. In Appendix A are briefly reported some concepts and results about Discrete Event Systems which should help the reader in understanding some crucial points in chapter 5; while in Appendix B an overview on the experimental testbed of the Laboratory of Automation of University of Bologna, is reported to validated the approach presented in chapter 3, chapter 4 and chapter 5. In Appendix C some components model used in chapter 5 for formal verification are reported.

Weiterentwicklung einer Produktionsanlage und der Speicherungs- bzw. Transportkonzepte für hochpolarisiertes 3He

Der Bedarf an hyperpolarisiertem 3He in Medizin und physikalischer Grundlagenforschung ist in den letzten ca. 10-15 Jahren sowohl in Bezug auf die zu Verfügung stehende Menge, als auch auf den benötigten Grad der Kernspinpolarisation stetig gestiegen. Gleichzeitig mußten Lösungen für die polarisationserhaltende Speicherung und den Transport gefunden werden, die je nach Anwendung anzupassen waren. Als Ergebnis kann mit dieser Arbeit ein in sich geschlossenes Gesamtkonzept vorgestellt werden, daß sowohl die entsprechenden Mengen für klinische Anwendungen, als auch höchste Polarisation für physikalische Grundlagenfor-schung zur Verfügung stellen kann. Verschiedene unabhängige Polarimetriemethoden zeigten in sich konsistente Ergebnisse und konnten, neben ihrer eigenen Weiterentwicklung, zu einer verläßlichen Charakterisierung des neuen Systems und auch der Transportzellen und –boxen eingesetzt werden. Die Polarisation wird mittels „Metastabilem Optischen Pumpen“ bei einem Druck von 1 mbar erzeugt. Dabei werden ohne Gasfluß Werte von P = 84% erreicht. Im Flußbetrieb sinkt die erreichbare Polarisation auf P ≈ 77%. Das 3He kann dann weitgehend ohne Polarisationsver-luste auf mehrere bar komprimiert und zu den jeweiligen Experimenten transportiert werden. Durch konsequente Weiterentwicklung der vorgestellten Polarisationseinheit an fast allen Komponenten kann somit jetzt bei einem Fluß von 0,8 barl/h eine Polarisation von Pmax = 77% am Auslaß der Apparatur erreicht werden. Diese skaliert linear mit dem Fluß, sodaß bei 3 barl/h die Polarisation immer noch bei ca. 60% liegt. Dabei waren die im Rahmen dieser Arbeit durchgeführten Verbesserungen an den Lasern, der Optik, der Kompressionseinheit, dem Zwischenspeicher und der Gasreinigung wesentlich für das Erreichen dieser Polarisatio-nen. Neben dem Einsatz eines neuen Faserlasersystems ist die hohe Gasreinheit und die lang-lebige Kompressionseinheit ein Schlüssel für diese Leistungsfähigkeit. Seit Herbst 2001 er-zeugte das System bereits über 2000 barl hochpolarisiertes 3He und ermöglichte damit zahl-reiche interdisziplinäre Experimente und Untersuchungen. Durch Verbesserungen an als Prototypen bereits vorhandenen Transportboxen und durch weitgehende Unterdrückung der Wandrelaxation in den Transportgefäßen aufgrund neuer Erkenntnisse über deren Ursachen stellen auch polarisationserhaltende Transporte über große Strecken kein Problem mehr dar. In unbeschichteten 1 Liter Kolben aus Aluminosilikatglä-sern werden nun problemlos Speicherzeiten von T1 > 200h erreicht. Im Rahmen des europäi-schen Forschungsprojektes „Polarized Helium to Image the Lung“ wurden während 19 Liefe-rungen 70barl 3He nach Sheffield (UK) und bei 13 Transporten 100 barl nach Kopenhagen (DK) per Flugzeug transportiert. Zusammenfassend konnte gezeigt werden, daß die Problematik der Kernspinpolarisationser-zeugung von 3He, die Speicherung, der Transport und die Verwendung des polarisierten Ga-ses in klinischer Diagnostik und physikalischen Grundlagenexperimenten weitgehend gelöst ist und das Gesamtkonzept die Voraussetzungen für allgemeine Anwendungen auf diesen Gebieten geschaffen hat.

Development of glass-ceramics from combination of industrial wastes together with boron mining waste

The utilization of borate mineral wastes with glass-ceramic technology was first time studied and primarily not investigated combinations of wastes were incorporated into the research. These wastes consist of; soda lime silica glass, meat bone and meal ash and fly ash. In order to investigate possible and relevant application areas in ceramics, kaolin clay, an essential raw material for ceramic industry was also employed in some studied compositions. As a result, three different glass-ceramic articles obtained by using powder sintering method via individual sintering processes. Light weight micro porous glass-ceramic from borate mining waste, meat bone and meal ash and kaolin clay was developed. In some compositions in related study, soda lime silica glass waste was used as an additive providing lightweight structure with a density below 0.45 g/cm3 and a crushing strength of 1.8±0.1 MPa. In another study within the research, compositions respecting the B2O3–P2O5–SiO2 glass-ceramic ternary system were prepared from; borate wastes, meat bone and meal ash and soda lime silica glass waste and sintered up to 950ºC. Low porous, highly crystallized glass-ceramic structures with density ranging between 1.8 ± 0,7 to 2.0 ± 0,3 g/cm3 and tensile strength ranging between 8,0 ± 2 to 15,0 ± 0,5 MPa were achieved. Lastly, diopside - wollastonite (SiO2-Al2O3-CaO )glass-ceramics from borate wastes, fly ash and soda lime silica glass waste were successfully obtained with controlled rapid sintering between 950 and 1050ºC. The wollastonite and diopside crystal sizes were improved by adopting varied combinations of formulations and heating rates. The properties of the obtained materials show; the articles with a uniform pore structure could be useful for thermal and acoustic insulations and can be embedded in lightweight concrete where low porous glass-ceramics can be employed as building blocks or additive in cement and ceramic industries.

Galactic fountain flows in high-resolution hydrodynamical simulations of galaxy disks

Feedback from the most massive components of a young stellar cluster deeply affects the surrounding ISM driving an expanding over-pressured hot gas cavity in it. In spiral galaxies these structures may have sufficient energy to break the disk and eject large amount of material into the halo. The cycling of this gas, which eventually will fall back onto the disk, is known as galactic fountains. We aim at better understanding the dynamics of such fountain flow in a Galactic context, frame the problem in a more dynamic environment possibly learning about its connection and regulation to the local driving mechanism and understand its role as a metal diffusion channel. The interaction of the fountain with a hot corona is hereby analyzed, trying to understand the properties and evolution of the extraplanar material. We perform high resolution hydrodynamical simulations with the moving-mesh code AREPO to model the multi-phase ISM of a Milky Way type galaxy. A non-equilibrium chemical network is included to self consistently follow the evolution of the main coolants of the ISM. Spiral arm perturbations in the potential are considered so that large molecular gas structures are able to dynamically form here, self shielded from the interstellar radiation field. We model the effect of SN feedback from a new-born stellar cluster inside such a giant molecular cloud, as the driving force of the fountain. Passive Lagrangian tracer particles are used in conjunction to the SN energy deposition to model and study diffusion of freshly synthesized metals. We find that both interactions with hot coronal gas and local ISM properties and motions are equally important in shaping the fountain. We notice a bimodal morphology where most of the ejected gas is in a cold $10^4$ K clumpy state while the majority of the affected volume is occupied by a hot diffuse medium. While only about 20\% of the produced metals stay local, most of them quickly diffuse through this hot regime to great scales.

Staphylococcus rostri sp. nov., a haemolytic bacterium isolated from the noses of healthy pigs

Twenty coagulase-negative Staphylococcus strains displaying alpha-haemolysis (delta-haemolysin) on sheep-blood agar were isolated from the noses of different pigs in Switzerland. The strains were Gram-stain-positive, non-motile cocci, catalase-positive and coagulase-negative. Sequence analysis of the 16S rRNA gene, sodA, rpoB, dnaJ and hsp60 and phylogenetic characteristics revealed that the strains showed the closest relatedness to Staphylococcus microti CCM 4903(T) and Staphylococcus muscae DSM 7068(T). The strains can be differentiated from S. microti by the absence of mannose fermentation and arginine arylamidase and from S. muscae by the absence of beta-glucuronidase activity and production of alkaline phosphatase. The chosen type strain ARI 262(T) shared 20.1 and 31.9 % DNA relatedness with S. microti DSM 22147(T) and S. muscae CCM 4903(T), respectively, by DNA-DNA hybridization. iso-C(15 : 0), anteiso-C(15 : 0) and iso-C(17 : 0) were the most common fatty acids. Cell-wall structure analysis revealed the peptidoglycan type A3alpha l-Lys-Gly(2)-l-Ser-Gly (type A11.3). The presence of teichoic acid was determined by sequencing the N-acetyl-beta-d-mannosaminyltransferase gene tarA, which is involved in biosynthesis of ribitol teichoic acid. Menaquinone 7 (MK-7) was the predominant respiratory quinone. The G+C content of ARI 262(T) was 38.8 mol%. The isolated strains represent a novel species of the genus Staphylococcus, for which we propose the name Staphylococcus rostri sp. nov. The type strain is ARI 262(T) (=DSM 21968(T) =CCUG 57266(T)) and strain ARI 602 (=DSM 21969 =CCUG 57267) is a reference strain.

The Extraction of Chromate Salts from Montana Chromite

In this thesis I have tried to determine the suit­able temperature, time and the amount of soda ash and lime needed for the calcining process. The leaching and purification tests were studied experimentally. The earlier process for making chromate from chromite was not the same as is used today. There­fore I have found it useful to put into this thesis the newest method for making chromate salts and their important uses.

GROUND-BASED AND SATELLITE REMOTE SENSING OF PAROXYSMAL ERUPTIONS AT ETNA VOLCANO, 2011-2012.

Mt Etna's activity has increased during the last decade with a tendency towards more explosive eruptions that produce paroxysmal lava fountains. From January 2011 to April 2012, 25 lava fountaining episodes took place at Etna's New South-East Crater (NSEC). Improved understanding of the mechanism driving these explosive basaltic eruptions is needed to reduce volcanic hazards. This type of activity produces high sulfur dioxide (SO2) emissions, associated with lava flows and ash fall-out, but to date the SO2 emissions associated with Etna's lava fountains have been poorly constrained. The Ultraviolet (UV) Ozone Monitoring Instrument (OMI) on NASA's Aura satellite and the Atmospheric Infrared Sounder (AIRS) on Aqua were used to measure the SO2 loadings. Ground-based data from the Observatoire de Physique du Globe de Clermont-Ferrand (OPGC) L-band Doppler radar, VOLDORAD 2B, used in collaboration with the Italian National Institute of Geophysics and Volcanology in Catania (INGV-CT), also detected the associated ash plumes, giving precise timing and duration for the lava fountains. This study resulted in the first detailed analysis of the OMI and AIRS SO2 data for Etna's lava fountains during the 2011-2012 eruptive cycle. The HYSPLIT trajectory model is used to constrain the altitude of the observed SO2 clouds, and results show that the SO2 emission usually coincided with the lava fountain peak intensity as detected by VOLDORAD. The UV OMI and IR AIRS SO2 retrievals permit quantification of the SO2 loss rate in the volcanic SO2 clouds, many of which were tracked for several days after emission. A first attempt to quantitatively validate AIRS SO2 retrievals with OMI data revealed a good correlation for high altitude SO2 clouds. Using estimates of the emitted SO2 at the time each paroxysm, we observe a correlation with the inter-paroxysm repose time. We therefore suggest that our data set supports the collapsing foam (CF) model [1] as driving mechanism for the paroxysmal events at the NSEC. Using VOLDORAD-based estimates of the erupted magma mass, we observe a large excess of SO2 in the eruption clouds. Satellite measurements indicate that SO2 emissions from Etnean lava fountains can reach the lower stratosphere and hence could pose a hazard to aviation. [1] Parfitt E.A (2004). A discussion of the mechanisms of explosive basaltic eruptions. J. Volcanol. Geotherm. Res. 134, 77-107.

An investigation of the pica practices of pregnant women in Houston and Prairie View, Texas

Pregnant African American women are at higher risk of having a preterm delivery and/or a low birthweight infant. Many factors are associated with adverse pregnancy outcomes but a food habit that deserves further study in the causal process is pica, a craving for, and ingestion of, nonnutritive substances such as laundry starch, clay, dirt, or ice. This food habit is more common in the African American population but has not been adequately studied in relation to preterm and/or low birth weight infants.^ Mothers (n = 281) with infants less than one year of age who participated in the Special Supplementary Food Program for Women, Infants, and Children (WIC) at clinics in Houston and Prairie View, Texas were interviewed regarding pica practices during pregnancy, dietary practices, and some demographic indices. Hospital records were abstracted for health information on the mothers and infants, including birthweight and gestational age at birth of the infant.^ The subjects were 88.6% African American, 6.8% Hispanic, and 4.6% Caucasian. Overall prevalence of pica was 76.5%. Pica prevalence by substance(s) was as follows: ice 53.7%; ice and freezer frost 14.6%; other substances such as baking soda, baking powder, cornstarch, laundry starch, and clay or dirt 8.2%; and 23.5% reported no pica. The women who reported ice/freezer frost pica had a higher percentage of illegal drug use and alcohol use during pregnancy. The women who reported other pica substances had the lowest mean educational level, highest gravidity, and a higher percentage smoked during pregnancy.^ There were no significant differences in nutrient intakes measured by the mean 24-hour dietary recalls between women who reported ice pica (n = 103) and women who denied pica (n = 50). The women who reported ice/freezer frost pica or other pica substances had more food cravings and food dislikes during pregnancy than those who reported ice pica or no pica.^ There were no differences in mean birthweight or mean gestational age at birth of infants born to mothers from the three pica groups and the no pica group but regression analyses revealed a possible relationship between pica, low maternal hemoglobin at delivery, and preterm birth. ^

Evaluation of the association between cryptosporidiosis outbreaks and two interactive water fountain parks: Epidemiologic analysis and implications for public health

Background. A community-wide outbreak of cryptosporidiosis occurred in Dallas County during the summer of 2008. A subset of cases occurring with onset of illness within a 2 week interval was epidemiologically linked to 2 neighborhood interactive water fountain parks. ^ Methods. A case control study was conducted to evaluate risk factors associated with developing illness with cryptosporidiosis from the fountain parks. Cases were selected from a line list from the epidemiological study. The selection for the controls was either healthy family members or a daycare center nearby. Cases and controls were not matched. ^ Results. Interviews were completed for 44 fountain park attendees who met case definition and 54 community controls. Twenty-seven percent (27.3%) of the cases and 13.0% of the controls were between the ages of 0–4 years. Thirty-nine percent (38.6%) of the cases and 24.1% of the controls were between the ages of 5–13 years. Fourteen percent (13.6%) of the cases and 33.3% of the controls were between the ages of 14–31 years. Twenty percent (20.5%) of the cases and 29.6% of the controls were between the ages of 32–63 years. 47.7% of the cases and 42.6% of the controls were males. Fountain park attendees who reported having been splashed in the face with water were 10 times more likely to become ill than controls (OR = 10.0, 95% CI = 2.8–35.1). Persons who reported having swallowed water from the interactive fountains were 34 times more likely to become ill than controls (OR = 34.3, 95%CI = 9.3–125.7). ^ Conclusion. Prompt reporting of cases, identification of outbreak sources, and immediate implementation of remediation measures were critical in curtailing further transmission from these particular sites through the remainder of the season. This investigation underscores the potential for cryptosporidiosis outbreaks to occur in interactive fountain parks, and the need for enhanced preventive measures in these settings. Education of the public regarding avoidance of behaviors such as drinking water from interactive fountains is also an important component of public health prevention efforts. ^

An investigation into the relationship between screen time, consumption of advertised foods, and physical activity among Texas 4th grade elementary school children

Background. The high prevalence of obesity among children has spurred creation of a list of possible causative factors, including the advertising of foods of minimal nutritional value, a decrease in physical activity, and increased media use. Few studies show prevalence rates of these factors among large cohorts of children. ^ Methods. Using data from the 2004-2005 School Physical Activity and Nutrition project (SPAN), a secondary analysis of 7907 4th-grade children (mean age 9.74 years) was conducted. In addition, a comic-book–based intervention that addressed advertised food consumption, physical activity, and media use was developed and evaluated using a pre-post test design among 4th-grade children in an urban school district. ^ Results. Among a cohort of 4th-grade children across the state of Texas, children who had more than 2 hours of video game or computer time the previous day were more than twice as likely to drink soda and eat candy or pastries. In addition, children who watched more than 2 hours of TV the previous day were more than three times as likely to consume chips, punch, soda, candy, frozen desserts, or pastries (AOR 3.41, 95% CI: 1.58, 7.37). A comic-book based intervention held great promise and acceptance among 4th-grade children. Outcome evaluation showed that while results moved in a positive direction, they were not statistically significant. ^ Conclusion. Statistically significant associations were found between screen time and eating various types of advertised food. The comic book intervention was widely accepted by the children exposed to it, and pre-post surveys indicated they moved constructs in a positive direction. Further research is needed to look at more specific ways in which children are exposed to TV, and the relationship of the TV viewing time with their consumption of advertised foods. In addition, researchers should look at comic book interventions more closely and attempt to utilize them in more in studies with a longer follow-up time. ^

Food availability in the home and dietary intake of the Harris County Department of Education Head Start population

Background. The prevalence of obesity and overweight children has been an ongoing health epidemic in the US for the last several decades. The problem has consistently worsened and has disproportionately been the most prevalent among low socioeconomic status (SES) populations. Food availability in the home has been suggested to be a potential factor related to overweight and obesity, as availability is likely associated with intake. Food availability of low SES preschool aged children has not been well examined. The purpose of this study was to explore the food environment of the Harris County Department of Education (HCDE) Head Start population, and describe reported frequency of intake of particular food groups. The effect of food availability on reported intake was also examined.^ Methods. This was a cross-sectional study of secondary data analysis. Data obtained from 17 HCDE Head Start Centers was analyzed using PASW 18 Statistical Software. Demographic analyses included population, age, gender, race, parent occupation, type of home, and language spoken in the home. Descriptive statistics included reported availability of foods in the home as well as frequency of intake.^ Regression analysis examined the relationship of availability of foods on intake. The food categories included were: dark leafy green and orange vegetables, other vegetables, fruits, soda, salty snacks, and sweet snacks. For both vegetable categories reported intake of fresh, frozen, and canned vegetables were included. For the fruit category, intake of fresh, frozen, canned, and dried fruits were reported.^ Results. Results showed that 90-95% of parents reported having vegetables and fruits available in the home. However, the only significant relationship between availability and intake was for fresh fruit and dried fruit. No associations were seen among the vegetable groups. Other vegetables (bell peppers, eggplant, tomatoes, onions, iceberg lettuce, asparagus) that were frozen, approached significance for availability on intake, however once adjusted for confounders the relationship was no longer present. Among soda, salty snacks, and sweet snacks the only significant relationship was seen for soda availability and intake. Salty snacks and sweet snacks presence in the home was not a predictor of increased frequency of intake.^ Conclusions. This research supported the hypothesis that availability of foods has an impact on intake for fresh fruits, dried fruits and soda. No associations were seen for vegetables, salty snacks and sweet snacks. Additionally, most of the parents reported having fruits and vegetables in the home, but reported intakes were not meeting the Dietary Guidelines for Americans recommendations. Strengths of the study included the large sample size taken from numerous HCDE Head Start Centers. Limitations included questionable reliability of participant’s responses, ability to generalize to other populations, and the use of secondary data rather than prospectively collected data.^

Ethnic differences in food availability at home among 3--5 year old preschoolers attending Head Start centers in 2008

Background. The childhood obesity epidemic has disproportionately impacted the lives of low-income, minority preschoolers and their families. Research shows that parents play a major role as "gatekeepers" who control what food is brought into the home and as role models for dietary practices. Currently, there is limited research regarding ethnic differences in families of low-income preschoolers. ^ Objective. The objective of this study was to look at ethnic differences in food availability at home among the low-income families of Hispanic and African American preschoolers attending Head Start centers in Harris County, Texas. ^ Design/Subjects. Descriptive data on food availability at home between Hispanic and African American families were used and analyzed for this study. Parents or primary caregivers (n = 718) of children enrolled at Head Start Centers in Houston, Texas completed the Healthy Home Survey. ^ Methods. In the Healthy Home Survey, participants were asked to answer open-ended questions regarding various types of foods currently available at home, such as fresh, canned or jarred, dried and frozen fruits; fresh, canned or jarred, and frozen vegetables; salty snacks, sweet snacks, candy, and soda. Descriptive analyses were conducted to identify significant differences between Hispanics and African Americans via a paired t-test to compare the means of variables between the study groups and a Pearson's chi-square or Fischer's exact (if cell size was <5) test calculated for food availability (food types) between ethnicities to determine differences in distributions. ^ Results. Although both Hispanics and African Americans reported having all categories of food types at home, there were statistically significant differences between ethnic groups. Hispanics were more likely to have fresh fruits and vegetables at home than African Americans. At the same time, more African American families reported having canned or jarred fruits and canned green/leafy vegetables than Hispanics. More Hispanic families reported having diet, regular, and both diet and regular sodas available compared to African American families. However, high percentages of unhealthy foods (including snacks and candy) were reported by both ethnicities. ^ Conclusions. The findings presented in this study indicate the implicit ethnic differences that exist in the food availability among low-income families of Hispanic and African American preschoolers. Future research should investigate the associations between food availability and children's weight status by ethnicity to identify additional differences that may exist.^