Seebeck Coefficients in Nanoscale Junctions: Effects of Electron-vibration Scattering and Local Heating

We report first-principles calculations of inelastic Seebeck coefficients in an aluminum monatomic junction. We compare the elastic and inelastic Seebeck coefficients with and without local heating. In the low temperature regime, the signature of normal modes in the profiles of the inelastic Seebeck effects is salient. The inelastic Seebeck effects are enhanced by the normal modes, and further magnified by local heating. In the high temperature regime, the inelastic Seebeck effects are weakly suppressed due to the quasi-ballistic transport.Comment: 3 Figure

Preschool children\u27s information processing and emotional behavior in social conflict situations

This study investigated various aspects of the Social Information Processing Model, in particular, young children’s emotional behavior regulation and negative emotionality, in Hong Kong. The sample was N=628 from 12 schools. Using Rasch measurement, linear unidimensional scales were constructed for Emotion and Behaviour Regulation (10 items) and for Negative Emotionality (10 items). The well-known Short Temperament Scale was Rasch analyzed too, but a linear scale could not be created – it had initially been designed under the True Score Test theory paradigm. The children were divided into Type A (high on negative emotionality and low on emotion and behavior regulation, N=27 and Type B (low on negative emotionality and high on emotion and behavior regulation, N=31). The children’s teachers were given conflict situations and asked to state what strategies the Type A and Type B children would adopt in each conflict situation. The first conflict situation was about the child who was being accidentally pushed by a peer. The second conflict situation was about the child who is being excluded from a game that has enough participants. The third conflict situation was about the child being called “a baby” because he/she was playing with baby toys. The fourth conflict situation was about a peer criticizing and putting marks on a child’s picture. The fifth situation was about a peer pushing ahead and taking a toy that a child has been waiting for a long time. The Type A and Type B children were also asked to state what strategies they would adopt in each conflict situation. When the teachers’ views were compared to the children’s views, it was clear that the teachers did not know their children’s thought processes very well. For both Type A and Type B children, Rasch analysis was used to create a calm/angry scale and a sad/happy scale. Conflict situation two (being excluded from a game) is very hard on the calm/angry scale and both Type A and Type B children need to have a very high angry measure to answer this item positively. Conflict situation two is moderately easy on the sad/happy scale and both Type A and Type B children need only a low sad measure to answer conflict situation two positively. In contrast, conflict situation three (being called a “baby”) is very hard on the sad/happy scale and both Type A and Type B children need to have a very high happy measure to answer this item positively. Conflict situation three is moderately easy on the calm/angry scale and both Type A and Type B children need only a low calm measure to answer conflict situation three positively. The present study gave strong support for the Social Information Processing Model and for the inclusion of emotion and behavior regulation and negative emotionality in the revised model. The study rejected the Short Temperament Scale as it did not produce a linear, unidimensional scale, and it showed that teachers do not know their children, in terms of strategies selection in common social conflict situations, as well as they think that they do. Children are much more conscious of the variety of strategies that can be used in common conflict situations than teachers would normally give them credit. Results indicate that levels of anger aroused in Type A children are associated with differences in the quality of strategies that they are able to generate for solving social problems. Type A and Type B children differ significantly in their choice of best strategy under different emotional conditions for the different conflict situations

285— Analysis of \u3ci\u3eher4.1\u3c/i\u3e in \u3ci\u3egef\u3c/i\u3e mutants

Zebrafish make an ideal model organism for studying the development of the retina and can help us understand and eventually create solutions for human eye diseases. The good effort (gef) mutant zebrafish have smaller eyes compared to the wild-type zebrafish embryos at 3 days post-fertilization. This is due to retinal degradation because of the lack of a functioning Chaf1b protein. The Chaf1b protein-coding region is disrupted due to the deletion of its coding intronic DNA which causes an exon to be lost. Chaf1b is important to the cell because it makes up one of the three parts of the chromosome assembly factor 1 (CAF-1). CAF-1 functions to regulate chromatin and load histones onto DNA, but cannot function without Chaf1b. While it has been hypothesized that Tp53-mediated apoptosis is responsible for the gef mutants’ small eyes, tp53-morphants and homozygous gef double mutants have been studied and the cell death seen in gef mutants is not correlated with Tp53 activity. Signaling pathway members Her4.1 and Ascl1a, promote retinal cell fate development. Histone deacetylases selectively regulate her4.1 and ascl1a mRNAs during retinal development, making these genes possible affected genes of the gef phenotype. Her4.1 was visualized in gef and wild-type zebrafish embryos via the in situ hybridization process

Contextual Motifs: Increasing the Utility of Motifs using Contextual Data

Motifs are a powerful tool for analyzing physiological waveform data. Standard motif methods, however, ignore important contextual information (e.g., what the patient was doing at the time the data were collected). We hypothesize that these additional contextual data could increase the utility of motifs. Thus, we propose an extension to motifs, contextual motifs, that incorporates context. Recognizing that, oftentimes, context may be unobserved or unavailable, we focus on methods to jointly infer motifs and context. Applied to both simulated and real physiological data, our proposed approach improves upon existing motif methods in terms of the discriminative utility of the discovered motifs. In particular, we discovered contextual motifs in continuous glucose monitor (CGM) data collected from patients with type 1 diabetes. Compared to their contextless counterparts, these contextual motifs led to better predictions of hypo- and hyperglycemic events. Our results suggest that even when inferred, context is useful in both a long- and short-term prediction horizon when processing and interpreting physiological waveform data.Comment: 10 pages, 7 figures, accepted for oral presentation at KDD '1

A Hypergraph-Based Machine Learning Ensemble Network Intrusion Detection System

Network intrusion detection systems (NIDS) to detect malicious attacks continues to meet challenges. NIDS are vulnerable to auto-generated port scan infiltration attempts and NIDS are often developed offline, resulting in a time lag to prevent the spread of infiltration to other parts of a network. To address these challenges, we use hypergraphs to capture evolving patterns of port scan attacks via the set of internet protocol addresses and destination ports, thereby deriving a set of hypergraph-based metrics to train a robust and resilient ensemble machine learning (ML) NIDS that effectively monitors and detects port scanning activities and adversarial intrusions while evolving intelligently in real-time. Through the combination of (1) intrusion examples, (2) NIDS update rules, (3) attack threshold choices to trigger NIDS retraining requests, and (4) production environment with no prior knowledge of the nature of network traffic 40 scenarios were auto-generated to evaluate the ML ensemble NIDS comprising three tree-based models. Results show that under the model settings of an Update-ALL-NIDS rule (namely, retrain and update all the three models upon the same NIDS retraining request) the proposed ML ensemble NIDS produced the best results with nearly 100% detection performance throughout the simulation, exhibiting robustness in the complex dynamics of the simulated cyber-security scenario.Comment: 12 pages, 10 figure

New Extinction and Mass Estimates from Optical Photometry of the Very Low Mass Brown Dwarf Companion CT Chamaeleontis B with the Magellan AO System

We used the Magellan adaptive optics (MagAO) system and its VisAO CCD camera to image the young low mass brown dwarf companion CT Chamaeleontis B for the first time at visible wavelengths. We detect it at r', i', z', and Ys. With our new photometry and Teff~2500 K derived from the shape its K-band spectrum, we find that CT Cha B has Av = 3.4+/-1.1 mag, and a mass of 14-24 Mj according to the DUSTY evolutionary tracks and its 1-5 Myr age. The overluminosity of our r' detection indicates that the companion has significant Halpha emission and a mass accretion rate ~6*10^-10 Msun/yr, similar to some substellar companions. Proper motion analysis shows that another point source within 2" of CT Cha A is not physical. This paper demonstrates how visible wavelength AO photometry (r', i', z', Ys) allows for a better estimate of extinction, luminosity, and mass accretion rate of young substellar companions.Comment: Accepted for publication in ApJ; 6 figure

New Extinction and Mass Estimates of the Low-mass Companion 1RXS 1609 B with the Magellan AO System: Evidence of an Inclined Dust Disk

We used the Magellan adaptive optics system to image the 11 Myr substellar companion 1RXS 1609 B at the bluest wavelengths to date (z' and Ys). Comparison with synthetic spectra yields a higher temperature than previous studies of $T_\mathrm{eff}=2000\pm100\mathrm{K}$ and significant dust extinction of $A_V=4.5^{+0.5}_{-0.7}$ mag. Mass estimates based on the DUSTY tracks gives 0.012-0.015 Msun, making the companion likely a low-mass brown dwarf surrounded by a dusty disk. Our study suggests that 1RXS 1609 B is one of the 25% of Upper Scorpius low-mass members harboring disks, and it may have formed like a star and not a planet out at 320 AU.Comment: 5 pages, 4 figures; accepted to ApJ