Three-dimensional distribution of nonmenthane hydrocarbons and halocarbons over the northwestern Pacific during the 1991 Pacific Exploratory Mission (PEM-West A)

A total of 1667 whole air samples were collected onboard the NASA DC-8 aircraft during the 6-week Pacific Exploratory Mission over the western Pacific (PEM-West A) in September and October 1991. The samples were assayed for 15 C2-C7 hydrocarbons and six halocarbons. Latitudinal (0.5°S to 59.5°N) and longitudinal (114°E to 122°W) profiles were obtained from samples collected between ground level and 12.7 km. Thirteen of the 18 missions exhibited at least one vertical profile where the hydrocarbon mixing ratios increased with altitude. Longitude-latitude color patch plots at three altitude levels and three-dimensional color latitudealtitude and longitude-altitude contour plots exhibit a significant number of middle-upper tropospheric pollution events. These and several lower tropospheric pollution plumes were characterized by comparison with urban data from Tokyo and Hong Kong, as well as with natural gas and the products from incomplete combustion. Elevated levels of nonmethane hydrocarbons (NMHC) and other trace gases in the upper-middle free troposphere were attributed to deep convection over the Asian continent and to typhoon-driven convection near the western Pacific coast of Asia. In addition, NMHCs and CH3CCI3 were found to be useful tracers with which to distinguish hydrocarbon and halocarbon augmented plumes emitted from coastal Asian cities into the northwestern Pacific

On Flux Quantization in F-Theory II: Unitary and Symplectic Gauge Groups

We study the quantization of the M-theory G-flux on elliptically fibered Calabi-Yau fourfolds with singularities giving rise to unitary and symplectic gauge groups. We seek and find its relation to the Freed-Witten quantization of worldvolume fluxes on 7-branes in type IIB orientifold compactifications on Calabi-Yau threefolds. By explicitly constructing the appropriate four-cycles on which to calculate the periods of the second Chern class of the fourfolds, we find that there is a half-integral shift in the quantization of G-flux whenever the corresponding dual 7-brane is wrapped on a non-spin submanifold. This correspondence of quantizations holds for all unitary and symplectic gauge groups, except for SU(3), which behaves mysteriously. We also perform our analysis in the case where, in addition to the aforementioned gauge groups, there is also a 'flavor' U(1)-gauge group.Comment: 33 pages, 4 figure

Art-making in a family medicine clerkship: how does it affect medical student empathy?

Background: To provide patient-centred holistic care, doctors must possess good interpersonal and empathic skills. Medical schools traditionally adopt a skills-based approach to such training but creative engagement with the arts has also been effective. A novel arts-based approach may help medical students develop empathic understanding of patients and thus contribute to medical students’ transformative process into compassionate doctors. This study aimed to evaluate the impact of an arts-making workshop on medical student empathy. Methods: This was a mixed-method quantitative-qualitative study. In the 2011-12 academic year, all 161 third year medical students at the University of Hong Kong were randomly allocated into either an arts-making workshop or a problem-solving workshop during the Family Medicine clerkship according to a centrally-set timetable. Students in the arts-making workshop wrote a poem, created artwork and completed a reflective essay while students in the conventional workshop problem-solved clinical cases and wrote a case commentary. All students who agreed to participate in the study completed a measure of empathy for medical students, the Jefferson Scale of Empathy (JSE) (student version), at the start and end of the clerkship. Quantitative data analysis: Paired t-test and repeated measures ANOVA was used to compare the change within and between groups respectively. Qualitative data analysis: Two researchers independently chose representational narratives based on criteria adapted from art therapy. The final 20 works were agreed upon by consensus and thematically analysed using a grounded theory approach. Results: The level of empathy declined in both groups over time, but with no statistically significant differences between groups. For JSE items relating to emotional influence on medical decision making, participants in the arts-making workshop changed more than those in the problem-solving workshop. From the qualitative data, students perceived benefits in arts-making, and gained understanding in relation to self, patients, pain and suffering, and the role of the doctor. Conclusions: Though quantitative findings showed little difference in empathy between groups, arts-making workshop participants gained empathic understanding in four different thematic areas. This workshop also seemed to promote greater self-awareness which may help medical students recognize the potential for emotions to sway judgment. Future art workshops should focus on emotional awareness and regulation.  published_or_final_versio

Design and analysis of a new HTS axial-field flux-switching machine

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Modeling of subharmonics and chaos in DC motor drives

In this paper, the nonlinear dynamics of both voltage-mode and current-mode controlled dc motor drive systems are presented. The investigation is based on the derivation of the discrete mappings that describe their system subharmonics and chaos in the continuous conduction mode of operation. It illustrates that different bifurcation diagrams can be obtained by using different modes of control while varying the same system parameters. A unified modeling approach for the period-1 and hence the period-p orbits as well as their stability analysis during both voltage-mode and current-mode of control is proposed and verified.published_or_final_versio

Preventing Advanced Persistent Threats in Complex Control Networks

An Advanced Persistent Threat (APT) is an emerging attack against Industrial Control and Automation Systems, that is executed over a long period of time and is difficult to detect. In this context, graph theory can be applied to model the interaction among nodes and the complex attacks affecting them, as well as to design recovery techniques that ensure the survivability of the network. Accordingly, we leverage a decision model to study how a set of hierarchically selected nodes can collaborate to detect an APT within the network, concerning the presence of changes in its topology. Moreover, we implement a response service based on redundant links that dynamically uses a secret sharing scheme and applies a flexible routing protocol depending on the severity of the attack. The ultimate goal is twofold: ensuring the reachability between nodes despite the changes and preventing the path followed by messages from being discovered.Universidad de Málaga. Campus de Excelencia Internacional Andalucía Tech

Tracking advanced persistent threats in critical infrastructures through opinion dynamics

Advanced persistent threats pose a serious issue for modern industrial environments, due to their targeted and complex attack vectors that are difficult to detect. This is especially severe in critical infrastructures that are accelerating the integration of IT technologies. It is then essential to further develop effective monitoring and response systems that ensure the continuity of business to face the arising set of cyber-security threats. In this paper, we study the practical applicability of a novel technique based on opinion dynamics, that permits to trace the attack throughout all its stages along the network by correlating different anomalies measured over time, thereby taking the persistence of threats and the criticality of resources into consideration. The resulting information is of essential importance to monitor the overall health of the control system and cor- respondingly deploy accurate response procedures. Advanced Persistent Threat Detection Traceability Opinion Dynamics.Universidad de Málaga. Campus de Excelencia Internacional Andalucía Tech

Physicochemical analysis of rotavirus segment 11 supports a 'modified panhandle' structure and not the predicted alternative tRNA-like structure (TRLS)

.Rotaviruses are a major cause of acute gastroenteritis, which is often fatal in infants. The viral genome consists of 11 double-stranded RNA segments, but little is known about their cis-acting sequences and structural elements. Covariation studies and phylogenetic analysis exploring the potential structure of RNA11 of rotaviruses suggested that, besides the previously predicted "modified panhandle" structure, the 5' and 3' termini of one of the isoforms of the bovine rotavirus UKtc strain may interact to form a tRNA-like structure (TRLS). Such TRLSs have been identified in RNAs of plant viruses, where they are important for enhancing replication and packaging. However, using tRNA mimicry assays (in vitro aminoacylation and 3'- adenylation), we found no biochemical evidence for tRNA-like functions of RNA11. Capping, synthetic 3' adenylation and manipulation of divalent cation concentrations did not change this finding. NMR studies on a 5'- and 3'-deletion construct of RNA11 containing the putative intra-strand complementary sequences supported a predominant panhandle structure and did not conform to a cloverleaf fold despite the strong evidence for a predicted structure in this conserved region of the viral RNA. Additional viral or cellular factors may be needed to stabilise it into a form with tRNA-like properties