Evaluation of non-contact sampling and detection of explosives using receiver operating characteristic curves

The growing need for fast sampling of explosives in high throughput areas has increased the demand for improved technology for the trace detection of illicit compounds. Detection of the volatiles associated with the presence of the illicit compounds offer a different approach for sensitive trace detection of these compounds without increasing the false positive alarm rate. This study evaluated the performance of non-contact sampling and detection systems using statistical analysis through the construction of Receiver Operating Characteristic (ROC) curves in real-world scenarios for the detection of volatiles in the headspace of smokeless powder, used as the model system for generalizing explosives detection. A novel sorbent coated disk coined planar solid phase microextraction (PSPME) was previously used for rapid, non-contact sampling of the headspace containers. The limits of detection for the PSPME coupled to IMS detection was determined to be 0.5-24 ng for vapor sampling of volatile chemical compounds associated with illicit compounds and demonstrated an extraction efficiency of three times greater than other commercially available substrates, retaining >50% of the analyte after 30 minutes sampling of an analyte spike in comparison to a non-detect for the unmodified filters. Both static and dynamic PSPME sampling was used coupled with two ion mobility spectrometer (IMS) detection systems in which 10-500 mg quantities of smokeless powders were detected within 5-10 minutes of static sampling and 1 minute of dynamic sampling time in 1-45 L closed systems, resulting in faster sampling and analysis times in comparison to conventional solid phase microextraction-gas chromatography-mass spectrometry (SPME-GC-MS) analysis. Similar real-world scenarios were sampled in low and high clutter environments with zero false positive rates. Excellent PSPME-IMS detection of the volatile analytes were visualized from the ROC curves, resulting with areas under the curves (AUC) of 0.85-1.0 and 0.81-1.0 for portable and bench-top IMS systems, respectively. Construction of ROC curves were also developed for SPME-GC-MS resulting with AUC of 0.95-1.0, comparable with PSPME-IMS detection. The PSPME-IMS technique provides less false positive results for non-contact vapor sampling, cutting the cost and providing an effective sampling and detection needed in high-throughput scenarios, resulting in similar performance in comparison to well-established techniques with the added advantage of fast detection in the field.

An experimental geochemical characterization analysis of archaeological iron from the contact period of Newfoundland and Labrador

This research uses scanning electron microscopy-energy dispersive X-ray spectrometry (SEM-EDX) and inductively coupled plasma-mass spectrometry (ICP-MS) on cross-sections of iron artifacts sectioned from along shafts to determine the elemental constituents of a collection of Inuit and European artifacts from along the coast of Labrador. Hand-wrought iron nails from early historic period (16th – 18th centuries CE) Inuit sites in Labrador were originally manufactured by and acquired from early whalers and fishers of various European nationalities. The purpose of this research was to assess if the elements in different samples are sufficiently homogeneous to be viable for a provenience analysis to discern which Inuit nails were originally derived from which European groups; the Basque, English or French. The consistent relationships between the geochemical signatures of iron nails found in Inuit sites and historic nails derived from specific European groups could provide insights into the prevalence, activity and the nature of indigenous interactions of different European nationalities in the region over time. The results show that the methods applied to evaluate the geochemistry of the nails was not sufficient to detect meaningful patterns because the nails did not demonstrate the necessary degree of chemical uniformity among different samples in the same artifacts.

Opportunistic Contact Graph Routing

L'ambiente di questa tesi è quello del Delay and Disruption Tolerant Networks (DTN), un'architettura di rete di telecomunicazioni avente come obiettivo le comunicazioni tra nodi di reti dette “challenged”, le quali devono affrontare problemi come tempi di propagazione elevati, alto tasso di errore e periodi di perdita delle connessioni. Il Bunde layer, un nuovo livello inserito tra trasporto e applicazione nell’architettura ISO/OSI, ed il protocollo ad esso associato, il Bundle Protocol (BP), sono stati progettati per rendere possibili le comunicazioni in queste reti. A volte fra la ricezione e l’invio può trascorrere un lungo periodo di tempo, a causa della indisponibilità del collegamento successivo; in questo periodo il bundle resta memorizzato in un database locale. Esistono varie implementazioni dell'architettura DTN come DTN2, implementazione di riferimento, e ION (Interplanetary Overlay Network), sviluppata da NASA JPL, per utilizzo in applicazioni spaziali; in esse i contatti tra i nodi sono deterministici, a differenza delle reti terrestri nelle quali i contatti sono generalmente opportunistici (non noti a priori). Per questo motivo all’interno di ION è presente un algoritmo di routing, detto CGR (Contact Graph Routing), progettato per operare in ambienti con connettività deterministica. È in fase di ricerca un algoritmo che opera in ambienti non deterministici, OCGR (Opportunistic Contact Graph Routing), che estende CGR. L’obiettivo di questa tesi è quello di fornire una descrizione dettagliata del funzionamento di OCGR, partendo necessariamente da CGR sul quale è basato, eseguire dei test preliminari, richiesti da NASA JPL, ed analizzarne i risultati per verificare la possibilità di utilizzo e miglioramento dell’algoritmo. Sarà inoltre descritto l’ambiente DTN e i principali algoritmi di routing per ambienti opportunistici. Nella parte conclusiva sarà presentato il simulatore DTN “The ONE” e l’integrazione di CGR e OCGR al suo interno.

Antecedentes artísticos de la danza "contact improvisation": visiones educativas de los "contacters"

Esta investigación tiene como objeto realizar un estudio de la danza Contact Improvisation (en adelante CI), teniendo en cuenta los antecedentes artísticos; considerar las visiones educativas de los contacters (personas que practican CI); y valorar las posibilidades de la danza CI, considerándola como herramienta útil para la educación. El CI es un envolvente sistema de movimiento iniciado en 1972 por el coreógrafo americano Steve Paxton. Una danza improvisada que se basa en la comunicación entre dos cuerpos que están en contacto y combinan la relación con las leyes físicas que gobiernan el movimiento – gravedad, impulso e inercia. La inquietud de encontrar nuevos caminos que ayuden al desarrollo de una educación más integral partiendo de procesos diferentes a los habituales, es lo que ha motivado este estudio; para ello, se pretende utilizar formas artísticas que aboguen y fomenten la libertad, la sensibilidad y la comunicación de forma creativa. En concreto, buscamos en el CI aspectos que sean favorables para una educación que, a diferencia de la educación reglada, le dé más importancia al desarrollo de la inteligencia emocional...

Woven cultures : New insights into Pictish and Viking culture contact using the implements of textile production

This paper is based on the undergraduate dissertation of Lindsey Stirling, which was supervised by Karen Milek, and which won the Society of Medieval Archaeology's John Hurst Memorial Dissertation Prize Acknowledgements This research would not have been possible without the assistance of Dr Martin Goldberg at the National Museum of Scotland, Lynda Aiano at Tankerness House Museum, Orkney, and Beverley Ballin Smith. The authors also wish to thank the two anonymous reviewers who provided valuable comments on earlier versions of this paper.

Woven cultures : New insights into Pictish and Viking culture contact using the implements of textile production

This paper is based on the undergraduate dissertation of Lindsey Stirling, which was supervised by Karen Milek, and which won the Society of Medieval Archaeology's John Hurst Memorial Dissertation Prize Acknowledgements This research would not have been possible without the assistance of Dr Martin Goldberg at the National Museum of Scotland, Lynda Aiano at Tankerness House Museum, Orkney, and Beverley Ballin Smith. The authors also wish to thank the two anonymous reviewers who provided valuable comments on earlier versions of this paper.

Dog-human dietary relationships in Yup'ik western Alaska : The stable isotope and zooarchaeological evidence from pre-contact Nunalleq

Acknowledgements This work was funded by a PhD studentship to EM from the Natural Environment Research Council (2210 GG005 RGA1521) and an Arts and Humanities Research Council (AH/K006029/1) grant to RK, KB and Charlotta Hillerdal (Aberdeen). Material was excavated from Nunalleq by staff and students from the University of Aberdeen, volunteer excavators and residents of Quinhagak. Logistical and planning support for the excavation was provided by Qanirtuuq Incorporated, Quinhagak, and the residents of Quinhagak.

Contact-mediated control of radial migration of corneal epithelial cells

We thank Darrin Sheppard and other staff at the University of Aberdeen Medical Research Facility for specialist technical assistance. We thank Patsy D. Goast for overnight microscope monitoring. This work was performed under the Biotechnology and Bioscience Research Council Grant number BB/E015840/1 to JMC.

Imagined intergroup contact facilitates intercultural communication for college students on academic exchange programs

Imagined intergroup contact (Crisp & Turner, 2009) is a new cognitive intervention designed to improve intergroup relations. In two studies, we examined whether it could also facilitate intercultural communication among international students and host country natives engaged in a college exchange program. In Study 1, international students who had recently arrived in Italy and participated in an imagined contact session displayed increased self-disclosure toward, and improved evaluation of, host country natives. In Study 2, Italian students mentally simulated positive contact with an unknown native from the host country prior to leaving for the exchange. Results from an online questionnaire administered on their return (on average, more than 7 months after the imagery task) revealed that participants who imagined contact reported spending more time with natives during the stay and enhanced outgroup evaluation, via reduced intergroup anxiety. Implications for enhancing the quality and effectiveness of college student exchange programs are discussed.

Bottom-up growth of fully transparent contact layers of indium tin oxide nanowires for light-emitting devices

Thin layers of indium tin oxide are widely used as transparent coatings and electrodes in solar energy cells, flat-panel displays, antireflection coatings, radiation protection and lithium-ion battery materials, because they have the characteristics of low resistivity, strong absorption at ultraviolet wavelengths, high transmission in the visible, high reflectivity in the far-infrared and strong attenuation in the microwave region. However, there is often a trade-off between electrical conductivity and transparency at visible wavelengths for indium tin oxide and other transparent conducting oxides. Here, we report the growth of layers of indium tin oxide nanowires that show optimum electronic and photonic properties and demonstrate their use as fully transparent top contacts in the visible to near-infrared region for light-emitting devices.

(Table 2, Page 275) Elemental concentrations in manganese nodules used in seawater contact experiments

The gross changes in concentrations of several trace elements in seawater after contact with ferro-manganese particle suspensions has been determined. Cobalt, Fe, and Zn concentrations in the seawater were greatly increased after contact with the par¬ticles. The concentrations of Rb, U, Cs, Sb, and Ag were altered to a lesser degree by this treatment. Similar results were observed where seawater was con¬tacted with suspensions of pelagic sediments. Of the trace elements measured, cobalt and iron appear to be the best elemental indicators of the presence of manganese mining effluents in the ocean. The addi¬tions of the essential elements Co, Fe and Zn toge¬ther with nutrients from the bottom waters may pro¬duce increased biological productivity. However, the toxic trace metals, such as Hg, Cu and Cd which could enter ocean water from the nodules and sedi¬ment and which may be high in effluent-affected areas should be investigated before conclusions as to the likely impact can be reached. Trace element analysis of seawater samples collected at a Pacific Ocean manganese nodule dredging site showed high t race element concentrations, but these are believed to have resulted from contamination during sample collection or storage rather than from the dredging operations.

By our tongues united? Irish and Scots language contact in rural Ulster

This article suggests that the impact of long-term language contact between the languages of Irish, Scots and English in the province of Ulster led to a hybridisation of accent which challenges traditional ethnolinguistic differentiations - namely, the myth that Catholics and Protestants can be differentiated by their accent. The digitisation of archive recordings from the Tape Recorded Survey of Hiberno-English (TRSHE) permitted a detailed phonetic analysis of two speakers from Atticall, a rural townland in the Mourne Mountains with a unique geographical and linguistic setting, due to the close proximity of Ulster Scots and Irish speakers in the area. Phonological features associated with Irish, Northern English and Lowland Scots were garnered from previous dialectological research in Irish, English and Scots phonologies, which aided with the interpretation of the data. Other contemporaneous recordings from the TRSHE allowed further comparison of phonological features with areas of Ulster in which linguistic interaction between Scots and Irish was expected to be less prevalent, such as Arranmore, Donegal (primarily Irish) and Glarryford, Antrim (primarily Scots). Accommodation theory and substrate/superstrate interaction illuminate patterns of phonological transfer in Mourne, Arranmore and Glarryford English, supporting the conclusion that accent in contemporary Northern Ireland is built upon a linguistic heritage of contact and exchange, rather than political or ethnolinguistic division

Collectively coping with contact: The role of intragroup support in dealing with the challenges of intergroup mixing in residential contexts

The social identity approach to stress has shown how intragroup support processes shape individuals' responses to stress across health care, workplace, and community settings. However, the issue of how these 'social cure' processes can help cope with the stress of intergroup contact has yet to be explored. This is particularly important given the pivotal role of intergroup threat and anxiety in the experience of contact as well as the effect of contact on extending the boundaries of group inclusion. This study applies this perspective to a real-life instance of residential contact in a divided society. Semi-structured interviews with 14 Catholic and 13 Protestant new residents of increasingly mixed areas of Belfast city, Northern Ireland, were thematically analysed. Results highlight that transitioning to mixed communities was fraught with intergroup anxiety, especially for those coming from 'single identity' areas. Help from existing residents, especially when offered by members of other religious denominations, signalled a 'mixed community ethos' to new residents, which facilitated adopting and sharing this identity. This shared identity then enabled them to deal with unexpected intergroup threats and provided resilience to future sectarian division. New residents who did not adopt this shared identity remained isolated, fearful, and prone to negative contact.

Exploring the influences on classroom-based contact via shared education in Northern Ireland

Initiatives in intercultural education have frequently involved the promotion of contact between members of different groups as a means of improving intergroup relations. Experience from Northern Ireland suggests, however, that such schemes have often been organised and delivered in such a way that opportunities for sustained, high-quality contact are limited. This paper considers processes of contact in one relatively recent initiative, “shared education”, which involves collaboration between separate schools to deliver classes to Catholic and Protestant pupils in mixed groups. Employing qualitative methods of observation and interviewing to capture participants’ experiences of contact, the research explores the influences on the quality and frequency of cross-group interaction in the shared class. With findings highlighting the subject and pedagogy, teacher’s approach and classroom arrangement as key factors, the study offers suggestions for policy and practice to enhance opportunities for contact and relationship-building in mixed classes.

Simulation of Distributed Contact in String Instruments: a Modal Expansion Approach

Impactive contact between a vibrating string and a barrier is a strongly nonlinear phenomenon that presents several challenges in the design of numerical models for simulation and sound synthesis of musical string instruments. These are addressed here by applying Hamiltonian methods to incorporate distributed contact forces into a modal framework for discrete-time simulation of the dynamics of a stiff, damped string. The resulting algorithms have spectral accuracy, are unconditionally stable, and require solving a multivariate nonlinear equation that is guaranteed to have a unique solution. Exemplifying results are presented and discussed in terms of accuracy, convergence, and spurious high-frequency oscillations.