The Epistolary Story in Haskalah Literature: Isaac Euchel’s \u27Igrot Meshulam\u27

This study of the epistolary genre in Hebrew Haskalah literature examines several epistolary pieces published in Hameʾasef, the journal of German Haskalah. In particular, it looks at Isaac Euchel\u27s \u27Igrot Meshulam ben Uriyah Haʾeshtemoi,\u27 considered the first epistolary writing in modern Hebrew belle lettres

A clinical test for visual crowding

Crowding is a major limitation of visual perception. Because of crowding, a simple object, like a letter, can only be recognized if clutter is a certain critical spacing away. Crowding is only weakly associated with acuity. The critical spacing of crowding is lowest in the normal fovea, and grows with increasing eccentricity in peripheral vision. Foveal crowding is more prominent in certain patient groups, including those with strabismic amblyopia and apperceptive agnosia. Crowding may lessen with age during childhood as reading speed increases. The range of crowding predicts much of the slowness of reading in children with developmental dyslexia. There is tantalizing evidence suggesting that the critical spacing of crowding indicates neural density (participating neurons per square deg) in the visual cortex. Thus, for basic and applied reasons, it would be very interesting to measure foveal crowding clinically in children and adults with normal and impaired vision, and to track the development of crowding during childhood. While many labs routinely measure peripheral crowding as part of their basic research in visual perception, current tests are not well suited to routine clinical testing because they take too much time, require good fixation, and are mostly not applicable to foveal vision. Here we report a new test for clinical measurement of crowding in the fovea. It is quick and accurate, works well with children and adults, and we expect it to work well with dementia patients as well. The task is to identify a numerical digit, 1-9, using a new “Pelli” font that is identifiable at tiny width (0.02 deg, about 1 minarc, in normal adult fovea). This allows quick measurement of the very small (0.05 deg) critical spacing in the normal adult fovea, as well as with other groups that have higher critical spacing. Preliminary results from healthy adults and children are presented

Discounting the effect of memory on repeated measures of beauty judgment

The intrinsic variance of beauty judgment is key to modeling beauty ratings. However, in repeated measures of beauty, observers surely make use of what they remember. To test how memory contributes to repeated beauty ratings, we asked participants to rate 75 arbitrarily named images (e.g., Fred). Initially, participants rated (1 to 7) how much beauty they felt from looking at a named image. Then participants completed two conditions. In the memory condition, participants saw only the name of an image and were asked to remember the image corresponding to that name and rate how much beauty they felt. In the repeat condition, they once again rated how much beauty they felt from looking at a named image. Lastly, in a memory check, participants tried to select which image was associated with a name. Only considering the correctly remembered trials (60%), we calculated the distribution of the differences between the initial beauty rating and that from either the memory condition or the repeat condition. The variance for the memory condition was more than double that of the repeat condition. Likewise, the initial beauty ratings predicted 84% of the variance in the repeat ratings but only 30% of the variance in the memory ratings. Cue combination studies report that observers typically combine cues by the optimal Bayesian rule: The combined reliability is the sum of the separate reliabilities for each cue, where reliability is one over variance. Assuming optimal combination of memory and immediate-perception judgment, we can discount the contribution of memory to estimate the variance of the immediate-perception judgment. Thus, in our paradigm the 0.83 variance of the repeated beauty rating corresponds to a 0.97 immediate-perception judgment variance (without memory). Overall, since there also was no significant difference in means, our results indicate that memory contributes little to repeated beauty ratings

Oscillatory activity in the infant brain reflects object maintenance

The apparent failure of infants to understand "object permanence" by reaching for hidden objects is perhaps the most striking and debated phenomenon in cognitive development. Of particular interest is the extent to which infants perceive and remember objects in a similar way to that of adults. Here we report two findings that clarify infant object processing. The first is that 6-mo-old infants are sensitive to visual cues to occlusion, particularly gradual deletion. The second finding is that oscillatory electroencephalogram activity recorded over right temporal channels is involved in object maintenance. This effect occurs only after disappearance in a manner consistent with occlusion and the object's continued existence

Cyclic Mobility Effects on Soil-Pile Interaction in Dense Sand

A methodology to evaluate the effects of earthquake-induced cyclic mobility in dense sand on the soil-pile interaction parameters is presented. The soil behavior under cyclic loading is defined based on the interpretation of consolidated-undrained cyclic triaxial tests on samples reconstituted to the in situ relative density and shear wave velocity. The stress distribution around the pile is determined analytically, and the softened zone is modelled by an annulus of softer soil. The application of this methodology for the design of three submerged-floating tunnels in the Messina straits, Italy, indicated that even in dense sand the foundation stiffness reduction can be considerable during an earthquake. Comparisons with different approaches available from the literature are discussed

Compensating point defects in 4He+ -irradiated InN

We use positron annihilation spectroscopy to study 2 MeV 4He+ -irradiated InN grown by molecular-beam epitaxy and GaN grown by metal-organic chemical-vapor deposition. In GaN, the Ga vacancies act as important compensating centers in the irradiated material, introduced at a rate of 3600 cm exp −1. The In vacancies are introduced at a significantly lower rate of 100cm−1, making them negligible in the compensation of the irradiation-induced additional n-type conductivity in InN. On the other hand, negative non-open volume defects are introduced at a rate higher than 2000cm exp −1. These defects are tentatively attributed to interstitial nitrogen and may ultimately limit the free-electron concentration at high irradiation fluences.Peer reviewe

Error-Free 10.7 Gb/s Digital Transmission over 2 km Optical Link Using an Ultra-Low-Voltage Electro-Optic Modulator

We demonstrate the feasibility of 10.7 Gb/s error-free (BER < 10-12) optical transmission on distances up to 2 km using a recently developed ultra-low-voltage commercial Electro-Optic Modulator (EOM) that is driven by 0.6 Vpp and with an optical input power of 1 mW. Given this low voltage operation, the modulator could be driven directly from the detectors’ board signals without the need of any further amplification reducing significantly the power dissipation and the material budget

Planar coupling to high-Q lithium niobate disk resonators

We demonstrate optical coupling to high-Q lithium niobate disks from an integrated lithium niobate waveguide. The waveguides are made by proton exchange in X-cut lithium niobate substrate. The disks with diameter of 4.7 mm and thickness of 1 mm are made from commercial Z-cut lithium niobate wafers by polishing the edges into a spheroidal profile. Both resonance linewidth and cavity ringdown measurements were performed to calculate the Q factor of the resonator, which is in excess of 10(8). Planar coupling represents the most promising technique for practical applications of whispering gallery mode resonators