2,239 research outputs found
Increased susceptibility to proactive interference in adults with dyslexia?
Recent findings show that people with dyslexia have an impairment in serial-order memory. Based on these findings, the present study aimed to test the hypothesis that people with dyslexia have difficulties dealing with proactive interference (PI) in recognition memory. A group of 25 adults with dyslexia and a group of matched controls were subjected to a 2-back recognition task, which required participants to indicate whether an item (mis)matched the item that had been presented 2 trials before. PI was elicited using lure trials in which the item matched the item in the 3-back position instead of the targeted 2-back position. Our results demonstrate that the introduction of lure trials affected 2-back recognition performance more severely in the dyslexic group than in the control group, suggesting greater difficulty in resisting PI in dyslexia.Peer reviewedFinal Accepted Versio
DAC-Less amplifier-less generation and transmission of QAM signals using sub-volt silicon-organic hybrid modulators
We demonstrate generation and transmission of optical signals by directly interfacing highly efficient silicon-organic hybrid (SOH) modulators to binary output ports of a field-programmable gate array. Using an SOH Mach-Zehnder modulator (MZM) and an SOH IQ modulator we generate ON-OFF- keying and binary phase-shift keying signals as well as quadrature phase-shift keying and 16-state quadrature amplitude modulation (16QAM) formats. Peak-to-peak voltages amount to only 0.27 V-pp for driving the MZM and 0.41 V-pp for the IQ modulator. Neither digital-to-analog converters nor drive amplifiers are required, and the RF energy consumption in the modulator amounts to record-low 18 fJ/bit for 16QAM signaling
Modeling of chemical processes in the low pressure capacitive RF discharges in a mixture of Ar/C2H2
We study the properties of a capacitive 13.56 MHz discharge properties with a
mixture of Ar/C2H2 taking into account the plasmochemistry and growth of heavy
hydrocarbons. A hybrid model was developed to combine the kinetic description
for electron motion and the fluid approach for negative and positive ions
transport and plasmochemical processes. A significant change of plasma
parameters related to injection of 5.8% portion of acetylene in argon was
observed and analyzed. We found that the electronegativity of the mixture is
about 30%. The densities of negatively and positively charged heavy
hydrocarbons are sufficiently large to be precursors for the formation of
nanoparticles in the discharge volume.Comment: 11 pages, 14 figure
Ultra-short silicon-organic hybrid (SOH) modulator for bidirectional polarization-independent operation
We propose a bidirectional, polarization-independent, recirculating IQ-modulator scheme based on the silicon-organic hybrid (SOH) platform. We demonstrate the viability of the concept by using an SOH Mach-Zehnder modulator, operated at 10 GBd BPSK and 2ASK-2PSK
A selected ion flow tube study of the reactions of gas-phase cations with PSCl3
A selected ion flow tube was used to investigate the positive ion chemistry of thiophosphoryl chloride, PSCl. Rate coefficients and ion product branching ratios have been determined at room temperature for reactions with nineteen cations ; HO, CF, CF, NO, NO, SF, SF, CF, O, HO, NO, O, CO, CO, N, N, Ar, F and Ne (in order of increasing recombination energy). Complementary data described in the previous paper have been obtained for this molecule via the observation of threshold photoelectron photoion coincidences. For ions whose recombination energies are in the range 10-22 eV, comparisons are made between the product ion branching rations of PSCl from photoionisation and from ion-molecule reactions. In most instances, the data from the two experiments are well correlated, suggesting that long-range charge transfer is the dominant mechanism for these ion-molecule reactions ; the agreement is particularly good for the atomic ions Ar, F and Ne. Some reactions (e.g. O + PSCl), however, exhibit significant differences; short-range charge transfer must then be occurring following the formation of an ion-molecule complex. For ions whose recombination energies are less than 10 eV (i.e. HO, CF, CF and NO), reactions can only occur via a chemical process in which bonds are broken and formed, because the recombination energy of the cation is less than the ionisation energy of PSCl
Loosening the reins or tightening them?:Complex relationships between parenting, effortful control, and adolescent psychopathology
Background Adolescents face major developmental tasks such as increasing individuation and establishing autonomy. These developmental tasks increase demands on adolescent self-control, hereby putting youth with poor effortful control at risk for psychopathology. Specific parenting behaviors might be warranted to buffer against this risk. Objective This study was designed to examine parenting-related risk and protective factors in the associations between effortful control and adolescent psychopathology. We hypothesized that youth with poor effortful control require more parental involvement (i.e., lower autonomy granting) to help complete these developmental tasks and subsequently avoid psychopathology. Methods Via adolescent self-reports (N = 809), associations between effortful control, perceived parenting (i.e., psychological control and autonomy support), and externalizing (i.e., interpersonal aggression and rule-breaking) and internalizing problems (i.e., depressive and anxiety problems) were examined. Results Regression analyses supported our hypothesis in boys: higher levels of autonomy support exacerbated the negative association between effortful control and rule-breaking. In contrast, in girls this was the case for lower levels of autonomy support. For both genders, low autonomy support and psychological control exacerbated negative associations between effortful control and internalizing problems. No buffering effects of parenting were found. Conclusions Low effortful control is associated with psychopathology in adolescents, but parenting can affect this association in several ways, depending on the type of psychopathology and the adolescent’s gender. Future research should focus on finding ‘optimal’ levels of parental control that can help avoid psychopathological problems in youth with poor effortful control
Spin-dependent resonant tunneling through semimetallic ErAs quantum wells
Resonant tunneling through semimetallic ErAs quantum wells embedded in GaAs
structures with AlAs barriers was recently found to exhibit an intriguing
behavior in magnetic fields which is explained in terms of tunneling selection
rules and the spin-polarized band structure including spin-orbit coupling.Comment: 4 pages, figures supplied as self-unpacking figures.uu, uses
epsfig.sty to incorporate figures in preprin
Silicon-organic hybrid electro-optical devices
Organic materials combined with strongly guiding silicon waveguides open the route to highly efficient electro-optical devices. Modulators based on the so-called silicon-organic hybrid (SOH) platform have only recently shown frequency responses up to 100 GHz, high-speed operation beyond 112 Gbit/s with fJ/bit power consumption. In this paper, we review the SOH platform and discuss important devices such as Mach-Zehnder and IQ-modulators based on the linear electro-optic effect. We further show liquid-crystal phase-shifters with a voltage-length product as low as V pi L = 0.06 V.mm and sub-mu W power consumption as required for slow optical switching or tuning optical filters and devices
Grating-based optical fiber interfaces for silicon-on-insulator photonic integrated circuits
In this paper, we review our work on efficient interfaces between a silicon-on-insulator photonic IC and a single-mode optical fiber based on grating structures. Several device configurations are presented that provide high efficiency, polarization insensitive, and broadband optical coupling on a small footprint. The high alignment tolerance and the fact that the optical fiber interface is out-of-plane provide opportunities for easy packaging and wafer-scale testing of the photonic IC. Finally, an optical probe based on a grating structure defined on the fiber facet is described
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