Observer Placement for Source Localization: The Effect of Budgets and Transmission Variance

When an epidemic spreads in a network, a key question is where was its source, i.e., the node that started the epidemic. If we know the time at which various nodes were infected, we can attempt to use this information in order to identify the source. However, maintaining observer nodes that can provide their infection time may be costly, and we may have a budget $k$ on the number of observer nodes we can maintain. Moreover, some nodes are more informative than others due to their location in the network. Hence, a pertinent question arises: Which nodes should we select as observers in order to maximize the probability that we can accurately identify the source? Inspired by the simple setting in which the node-to-node delays in the transmission of the epidemic are deterministic, we develop a principled approach for addressing the problem even when transmission delays are random. We show that the optimal observer-placement differs depending on the variance of the transmission delays and propose approaches in both low- and high-variance settings. We validate our methods by comparing them against state-of-the-art observer-placements and show that, in both settings, our approach identifies the source with higher accuracy.Comment: Accepted for presentation at the 54th Annual Allerton Conference on Communication, Control, and Computin

A revision of the Neotropical predaceous midges of Brachypogon (Brachypogon) Kieffer (Diptera: Ceratopogonidae)

This revision of the Neotropical predaceous midges of the genus Brachypogon (Brachypogon) Kieffer, recognizes 18 extant species, including the following 12 new species: Brachypogon (B.) apunctipennis, bifidus, bimaculatus, ecuadorensis, ethelae, insularis, monicae, pseudoparaensis, schmitzi, spatuliformis, telesfordi, and woodruffi. Two species groups are recognized, the fuscivenosus and impar groups. The hitherto unknown male of B. paraensis Wirth & Blanton is described and illustrated, and the female of that species as well as both sexes of B. impar (Johannsen) and B. fuscivenosus (Lutz) are redescribed and illustrated. Diagnoses are provided for previously described species, as well as a key for the recognition of all Neotropical species. New records of B. impar are from Brazil, Colombia, and Argentina

Temporal precedence of emotion over attention modulations in the lateral amygdala: Intracranial ERP evidence from a patient with temporal lobe epilepsy

Previous fMRI studies have reported mixed evidence for the influence of selective attention on amygdala responses to emotional stimuli, with some studies showing "automatic" emotional effects to threat-related stimuli without attention (or even without awareness), but other studies showing a gating of amygdala activity by selective attention with no response to unattended stimuli. We recorded intracranial local field potentials from the intact left lateral amygdala in a human patient prior to surgery for epilepsy and tested, with a millisecond time resolution, for neural responses to fearful faces appearing at either task-relevant or task-irrelevant locations. Our results revealed an early emotional effect in the amygdala arising prior to, and independently of, attentional modulation. However, at a later latency, we found a significant modulation of the differential emotional response when attention was directed toward or away from fearful faces. These results suggest separate influences of emotion and attention on amygdala activation and may help reconcile previous discrepancies concerning the relative responsiveness of the human amygdala to emotional and attentional factors

Influence of cold storage time on the softening prediction in Spring Bright nectarines

With Time-resolved Reflectance Spectroscopy (TRS) the maturity of nectarines at harvest can be assessed by measuring the absorption coefficient at 670 nm (µa 670) in the fruit flesh. A kinetic model has been developed linking the optical properties as measured by TRS with the models of µa 670 and firmness decay in shelf-life at 20°C, making the prediction of the softening time for individual fruit possible. In order to study the influence of cold storage time prior to shelf life on the softening prediction, 540 (year 2003) and 870 (year 2004) ‘Spring Bright’ nectarines were measured at harvest with TRS; then fruit were put in shelf life after various periods of cold storage at 0°C (4 and 10 d, year 2003; 6, 13 and 20 days, year 2004). During the 5-day period of shelf life at 20°C, fruit were analysed for firmness by pressure test after 30, 48, 54, 72, 78, 96, 102 and 120h in 2003 and after 36, 43, 62, 87, 108 and 135h in 2004. For each year and cold storage time, the parameters of the logistic model of softening as a function of µa 670 at harvest were computed. The cold storage up to 13 days did not significantly influence the estimates of the softening rate constant (kf), of the maximum firmness at minus infinite time (Fmax) and of parameter alpha (a) in both years, whereas parameter beta (ß) in 2003 significantly decreased from -1.867 at day 4 to -2.237 at day 10. The further 7 days of cold storage in 2004 significantly affected kf, which decreased from 0.00084 at days 6 and 13 to 0.00069 at day 20, and ß which increased from -2.395 at day 6 to -2.053 at day 20. Our results indicate that the cold storage time significantly influences the softening prediction of nectarines as the longer the cold storage, the lower the softening rat

The biting and predaceous midges of Guadeloupe (Diptera: Ceratopogonidae). I. Species of the subfamily Ceratopogoninae

We provide new records of biting and predaceous midges (Diptera: Ceratopogonidae) from Guadeloupe in the subfamily Ceratopogoninae, including descriptions and illustrations of three new predaceous species in the genera, Parabezzia Malloch, Stilobezzia Kieffer and Palpomyia Meigen, respectively, and the first records of the New World predaceous genus, Amerohelea Grogan and Wirth, from the Caribbean region. We also provide the first Guadeloupe records of the biting midges, Culicoides (Anilomyia) decor (Williston), C. (Avaritia) pusillus Lutz, C. (Drymodesmyia) bredini Wirth and Blanton, C. (D.) poikilonotus Macfie, C. (Haematomyidium) hoffmani Fox, C. (Hoffmania) insignis Lutz, C. rangeli Ortiz and Mirsa and C. trilineatus Fox, and the predaceous midges, Brachypogon (Brachypogon) bifidus Spinelli and Grogan, B. (B.) telesfordi Spinelli and Grogan, B. (B.) woodruffi Spinelli and Grogan, Monohelea maya Felippe-Bauer, Huerta and Ibáñez-Bernal, Stilobezzia (Stilobezzia) diminuta Lane and Forattini, S. (S.) thomsenae Wirth, Amerohelea galindoi Grogan and Wirth, Bezzia (Bezzia) flinti Spinelli and Wirth, B. (Homobezzia) venustula (Williston) and Palpomyia insularis Spinelli and Grogan

TRS-measurements as a nondestructive method assessing stage of maturity and ripening in plum (Prunus domestica L.)

n plum fruit with dark red or blue blush colour covering the whole fruit, the change in ground colour from green to yellow during maturation and ripening is masked. Hence, the maturity stage is difficult to judge. Time-resolved reflectance spectroscopy (TRS) has been used as a nondestructive method to assess changes in important internal quality factors in ‘Jubileum’ plums (Prunus domestica L.). Absorption coefficients (µa) and scattering coefficients (µs) were measured at both 670 and 758 nm during 5 days of storage. The changes in soluble solids content, titratable acidity and firmness were as expected. No change in soluble solids content was observed, while the plums became less acid and softer during storage. The TRS-measurements of plums indicated that TRS could give interesting information on internal quality factors in plums as the absorption at 670 nm was closely related to firmness, TA and TSS at the time of picking. Absorption at 758 nm was more closely related to the quality parameters after storage. The study did not indicate that scattering could be used in assessing maturity stage in plum

Investigation of the RTN Distribution of nanoscale MOS devices from subthreshold to on-state

This letter presents a numerical investigation of the statistical distribution of the random telegraph noise (RTN) amplitude in nanoscale MOS devices, focusing on the change of its main features when moving from the subthreshold to the on-state conduction regime. Results show that while the distribution can be well approximated by an exponential behavior in subthreshold, large deviations from this behavior appear when moving toward the on-state regime, despite a low probability exponential tail at high RTN amplitudes being preserved. The average value of the distribution is shown to keep an inverse proportionality to channel area, while the slope of the high-amplitude exponential tail changes its dependence on device width, length, and doping when moving from subthreshold to on-state

A construção do currículo nacional e o conteúdo segundo professores de química brasileiros

Este trabalho visa analisar as contribuições de professores de Química à consulta pública da primeira versão da Base Nacional Comum Curricular (BNCC) e mapear representações sobre o currículo de Química no Ensino Médio brasileiro. O corpus textual com as contribuições, dividido em três subcorpora, foi analisado com o auxílio do software IRaMuTeQ, que permitiu dividir o texto em classes de segmentos de texto (ST) com conteúdo semântico semelhante. Os resultados mostram que as visões curriculares dos professores são fortemente estruturadas pelos conteúdos de ensino, e que muitas dessas visões ecoam a relação desses docentes com os currículos oficiais de suas próprias redes de ensino

A base nacional comum curricular e os resultados de sua consulta pública : uma leitura do componente curricular química

Este trabalho apresenta uma leitura comparativa entre a primeira versão da Base Nacional Comum Curricular (BNCC) e a consulta pública online a este texto com a participação de professores de todo o Brasil. Realizou-se uma análise lexicográfica com o software IRaMuTeQ, que permitiu dividir o texto em classes de segmentos de texto (ST) com conteúdo semântico semelhante. Os resultados mostram que as contribuições dos professores possuem uma estrutura compartimentada. Ademais, os verbos utilizados permitem inferir, a partir dos princípios da taxonomia de Bloom, que os contextos de utilização dos verbos remetem a processos cognitivos de ordem mais baixa do que os encontrados no texto da BNCC

Assessing the Harvest Maturity of Brazilian Mangoes

No clear criterion exists to determine the optimum time to harvest mango. Some empirical relations are used to assess maturity, such as shoulder development. Moreover, as a result of the typical growing conditions in tropical climates, a huge variation in maturity and ripeness exists, seriously hampering the export of fruit in the global chain. The consequence for consumers in western countries is that sometimes mangoes are overripe at the retailer, or have to be kept for several days, even weeks, to reach the edible state, provided they do not rot in the meantime. To ensure an edible quality, the chlorophyll content in the fruit flesh, measured at harvest by Time-resolved Reflectance Spectroscopy (TRS), could be used as a maturity criterion for mango fruit. Commercially grown fruit were harvested in Brazil and transported to Italy by plane. Fruits were measured using TRS at 630 nm for absorption coefficient (µa) and skin colour. The development of µa was followed on 60 fruits during 15 days of storage at 20°C. The remainders of fruit were used to measure firmness destructively. Absorption coefficient decreased during shelf life according to a logistic pattern, as expected for colour development. Taking the variation between the individual fruit into account, 72% of the variation was accounted for. Nevertheless, µa assessed at harvest could be converted into a biological shift factor (BSF), as an expression of the maturity at harvest of each individual fruit. This biological shift factor explained about 70% of the variation in firmness development in individual fruit. These preliminary results indicate that TRS methodology coupled with BSF theory could be useful in assessing maturity at harvest and assuring acceptable eating quality of mango