Microwave-mediated heat transport through a quantum dot

The thermoelectric effect in a quantum dot (QD) attached to two leads in the presence of microwave fields is studied by using the Keldysh nonequilibrium Green function technique. When the microwave is applied only on the QD and in the linear-response regime, the main peaks in the thermoelectric figure of merit and the thermopower are found to decrease, with the emergence of a set of photon-induced peaks. Under this condition the microwave field can not generate heat current or electrical bias voltage. Surprisingly, when the microwave field is applied only to one (bright) lead and not to the other (dark) lead or the QD, heat flows mostly from the dark to the bright lead, almost irrespectively to the direction of the thermal gradient. We attribute this effect to microwave-induced opening of additional transport channels below the Fermi energy. The microwave field can change both the magnitude and the sign of the electrical bias voltage induced by the temperature gradient.Comment: 5 figur

Life Tables of Bactrocera cucurbitae (Coquillett) (Diptera: Tephritidae): with a Mathematical Invalidation for Applying the Jackknife Technique to the Net Reproductive Rate

Life table data for the melon fly, Bactrocera cucurbitae (Coquillett), reared on cucumber (Cucumis sativus L.) were collected under laboratory and simulated field conditions. Means and standard errors of life table parameters were estimated for two replicates using the jackknife technique. At 25ºC, the intrinsic rates of increase (_r_) found for the two replicates were 0.1354 and 0.1002 day-1, and the net reproductive rates (_R_~0~) were 206.3 and 66.0 offspring, respectively. When the cucumbers kept under simulated field conditions were covered with leaves, the _r_ and _R_~0~ for the two replicates were 0.0935 and 0.0909 day-1, 17.5 and 11.4 offspring, respectively. However, when similar cucumbers were left uncovered, the _r_ and _R_~0~ for the two replicates were 0.1043 and 0.0904 day-1, and 27.7 and 10.1 offspring, respectively. Our results revealed that considerable variability between replicates in both laboratory and field conditions is possible; this variability should be taken into consideration in data collection and application of life tables. Mathematical analysis has demonstrated that applying the jackknife technique results in unrealistic pseudo-_R_~0~ and overestimation of its variance. We suggest that the jackknife technique should not be used for the estimation of variability of _R_~0~

Applying a Metacognitive Framework in the Neuropsychological Assessment of Subjective Cognitive Decline and Mild Cognitive Impairment

The characterization of the earliest stages of Alzheimer\u27s disease (AD) is a topic of major research interest because it is critical for early diagnosis and emerging interventions. Metamemory, or knowledge about memory, including awareness of one’s own memory functions, has been investigated in AD especially in relation to how impairment in memory and executive functions contribute to unawareness of cognitive deficits, termed anosognosia. Previous research, however, has not systematically investigated metamemory functioning in older adults with prodromal dementia conditions. Therefore, we investigated metamemory accuracy in cognitively healthy older adults (HC) and those with subjective cognitive decline but intact neuropsychological test scores (SCD), amnestic mild cognitive impairment (aMCI), and non-amnestic mild cognitive impairment (naMCI), all recruited from a longitudinal study of cognitive aging (Einstein Aging Study). Two studies respectively examined group differences in the accuracy of retrospective metamemory judgments (Empirical Study 1) and prospective metamemory judgments (Empirical Study 2) made during the monitoring of retrieval and encoding processes. Results showed that metamemory accuracy was weak in naMCI participants compared to controls, suggesting poor monitoring during both retrieval and encoding. In addition, although there was some evidence that retrospective monitoring processes may be suboptimal in aMCI compared to HC (Empirical Study 1), prospective metamemory monitoring processes were relatively intact in these individuals (Empirical Study 2), suggesting that performance monitoring of retrieval processes (which is more dependent on basic memory functions) may be differentially affected in aMCI. Furthermore, both studies revealed preserved metamemory accuracy in SCD, suggesting that performance monitoring of retrieval and encoding is intact in these older adults who present with subjective cognitive impairment and who may represent a pre-MCI condition. In addition, results revealed preserved memory self-awareness and self-knowledge in SCD (Empirical Study 2), providing further evidence that these individuals are capable of accurate self-assessment of their subjective experience of cognitive change. Overall, our novel findings support the hypothesis that metamemory performance varies across the neurodegenerative continuum and differentially impacts mechanisms in the metamemorial system that rely on memory (temporal lobe integrity) and/or executive functioning (prefrontal brain systems). Findings also inform remediation efforts such as the potential benefit of targeting specific metacognitive weaknesses (poor error detection, errors in evaluation during performance monitoring), in older adults with naMCI

Randomized Greedy Hot-Potato Routing on the Multi-Dimensional Torus

We present extensive simulation and analysis on a traditional, simple, efficient dynamic hot potato routing algorithm on a multi-dimensional torus network. These simulations are performed under a more recent network model than previous, more limited studies, with dynamic (rather than batch) models, no flow-control, and extended high dimensional scenarios. We collect more comprehensive statistics on system performance, and empirically show that the system can recover from worst-case scenarios to quickly re-achieve its standard steady-state delivery rates, with expected delivery time for a packet of O(n), where n is the initial packet distance from its destination. Experiments also show that for our model, the constant multiplier hidden in the O() notation decreases with higher dimensions

GraphSE2^2: An Encrypted Graph Database for Privacy-Preserving Social Search

In this paper, we propose GraphSE$^2$, an encrypted graph database for online social network services to address massive data breaches. GraphSE$^2$ preserves the functionality of social search, a key enabler for quality social network services, where social search queries are conducted on a large-scale social graph and meanwhile perform set and computational operations on user-generated contents. To enable efficient privacy-preserving social search, GraphSE$^2$ provides an encrypted structural data model to facilitate parallel and encrypted graph data access. It is also designed to decompose complex social search queries into atomic operations and realise them via interchangeable protocols in a fast and scalable manner. We build GraphSE$^2$ with various queries supported in the Facebook graph search engine and implement a full-fledged prototype. Extensive evaluations on Azure Cloud demonstrate that GraphSE$^2$ is practical for querying a social graph with a million of users.Comment: This is the full version of our AsiaCCS paper "GraphSE$^2$: An Encrypted Graph Database for Privacy-Preserving Social Search". It includes the security proof of the proposed scheme. If you want to cite our work, please cite the conference version of i