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Studies suggest that visual short-term memory (VSTM) is a continuous resource that can be flexibly allocated using probabilistic cues that indicate test likelihood (i.e., goal-directed attentional priority to those items). Previous studies using simultaneous cues have not examined this flexible allocation beyond two distinct levels of priority. Moreover, previous studies have not examined whether there are individual differences in the ability to flexibly allocate VSTM resources, as well as whether this ability benefits from practice. The current study used a continuous report procedure to examine whether participants can use up to three levels of attentional priority to allocate VSTM resources via simultaneous probabilistic spatial cues. Three experiments were performed with differing priority levels, cues, and cue presentation times. Group level analysis demonstrated flexible allocation of VSTM resources; however, there was limited evidence that participants could use three goal-directed priority levels. A temporal analysis suggested that task fatigue, rather than practice effects, may interact with item priority. A Bayesian individual-differences analysis revealed that a minority of participants were using three levels of attentional priority, demonstrating that, while possible, it is not the predominant pattern of behaviour. Thus, we provided evidence that flexible allocation to three attention levels is possible under simultaneous cuing conditions for a minority of participants. Flexible allocation to three categories may be interpreted as a skill of high-performing participants akin to high memory capacity. [ABSTRACT FROM AUTHOR]

The nitrogen isotope compositions of charred wheat and barley grains reflect manuring intensity and have been used to reconstruct past manuring practices at archaeological sites across Europe and western Asia. To assess whether this analytical method can be applied to a staple crop in the West African Sahel, the nitrogen isotope values of Pennisetum glaucum grains in this region were determined and the effect of charring ascertained. Pennisetum glaucum ears were collected from fields in northeast Senegal, where the fertilisation histories of the plots (manure and/or household waste) were known. The nitrogen isotope values of these millet grains provide an insight into the values to expect for P. glaucum grains grown with low to moderate addition of manure/household waste in a semi-arid climate. Charring of P. glaucum grains by heating at 215–260 °C for 4–24 h increases their nitrogen isotope values by a maximum of 0.34‰. In light of these modern data, the nitrogen isotope values of millet grains recovered from the archaeological settlement mound of Tongo Maaré Diabal, Mali, can be interpreted as evidence for modest levels of manure/household waste input throughout the occupation of the site from cal ad 500–1150. This study demonstrates the potential for nitrogen isotope values of P. glaucum grains to shed light on past farming practices in West Africa. [ABSTRACT FROM AUTHOR]

Working memory (WM) is impaired following sleep loss and may be improved after a nap. The goal of the current study was to better understand sleep-related WM enhancement by: (1) employing a WM task that assesses the ability to hold and report visual representations as well as the fidelity of the reports on a fine scale, (2) investigating neurophysiological properties of sleep and WM capacity as potential predictors or moderators of sleep-related enhancement, and (3) exploring frontal and occipital event-related delay activity to index the neural processing of stimuli in WM. In a within-subjects design, 36 young adults (Mage = 20, 20 men, 16 women) completed a 300-trial, continuous-report task of visual WM following a 90-min nap opportunity and an equivalent period of wakefulness. Mixed-effect models were used to estimate the odds of successful WM reports and the fidelity of those reports. The odds of a successful report were approximately equal between nap and wake conditions for the start of the task, but by the end, the odds of success were 1.26 times greater in the nap condition. Successful WM reports were more accurate after a nap, independent of the time on task. Neither WM capacity nor any of the sleep variables measured were found to significantly moderate the nap effect on WM. Lastly, napping resulted in amplitude changes for frontal and occipital delay activity relative to the wake condition. The findings are discussed in relation to contemporary models of visual WM and the role of sleep in sustained attention. [ABSTRACT FROM AUTHOR]

Chalcogenides—alloys based on group-16 ‘chalcogen’ elements (sulfur, selenium, and tellurium) covalently bound to ‘network formers’ such as arsenic, germanium, antimony, and gallium—have a variety of technologically useful properties, including infrared transparency, high optical nonlinearity, photorefractivity and readily induced, reversible, non-volatile structural phase switching. Such phase-change materials are of enormous interest in the fields of plasmonics and nanophotonics. However, in such applications, the fact that some chalcogenides accrue plasmonic properties in the transition from an amorphous to a crystalline state, i.e., the real part of their relative permittivity becomes negative, has gone somewhat unnoticed. Indeed, one of the most commercially important chalcogenide compounds, germanium antimony telluride (Ge2:Sb2:Te5 or GST), which is widely used in rewritable optical and electronic data storage technologies, presents this behavior at wavelengths in the near-ultraviolet to visible spectral range. In this work, we show that the phase transition-induced emergence of plasmonic properties in the crystalline state can markedly change the optical properties of sub-wavelength-thickness, nanostructured GST films, allowing for the realization of non-volatile, reconfigurable (e.g., color-tunable) chalcogenide metasurfaces operating at visible frequencies and creating opportunities for developments in non-volatile optical memory, solid state displays and all-optical switching devices. Inorganic compounds that transform on demand from glassy (dielectric) to crystalline (plasmonic) states can be employed to manipulate the color of reflected and transmitted light. The ability of germanium antimony telluride (GST) to change structural phase in response to brief laser heating pulses is the foundation of rewritable optical data storage technologies. Researchers from the University of Southampton, UK and Nanyang Technological University, Singapore, now report on a novel application of GST’s phase-change character to switching color. They etched a series of nanoscale grating patterns into a thin GST film, creating structures that control levels of reflection, transmission and absorption for different colors of light, in a way that changes when GST is switched between its amorphous and crystalline states. This type of laser-controlled color switching could benefit applications including solid-state display technologies. Phase change materials are of enormous interest in the field of plasmonics and nanophotonics. For such applications, it has gone largely unnoticed that some chalcogenides accrue plasmonic properties in the transition from an amorphous to a crystalline state. In this work, we show that the phase transition-induced emergence of plasmonic properties in the crystalline state can markedly change the optical properties of subwavelength-thickness nanostructured GeSbTe films, providing for the realization of non-volatile, reconfigurable (e.g. color-tunable) chalcogenide metasurfaces operating at visible frequencies, and thus creating opportunities for developments in non-volatile optical memory, solid state displays and all-optical switching devices. [ABSTRACT FROM AUTHOR]

Recently, coherent control of the optical response of thin films in standing waves has attracted considerable attention, ranging from applications in excitation-selective spectroscopy and nonlinear optics to all-optical image processing. Here, we show that integration of metamaterial and optical fibre technologies allows the use of coherently controlled absorption in a fully fiberized and packaged switching metadevice. With this metadevice, which controls light with light in a nanoscale plasmonic metamaterial film on an optical fibre tip, we provide proof-of-principle demonstrations of logical functions XOR, NOT and AND that are performed within a coherent fibre network at wavelengths between 1530 and 1565 nm. The metadevice has been tested at up to 40 gigabits per second and sub-milliwatt power levels. Since coherent absorption can operate at the single-photon level and with 100 THz bandwidth, we argue that the demonstrated all-optical switch concept has potential applications in coherent and quantum information networks. [ABSTRACT FROM AUTHOR]

A correction is presented to the article, The "Default Hypothesis" Fails to Explain Jewish Influence which appeared in 11 April 2021 issue.

This article contrasts policy intent and policy implementation in school autonomy and accountability. The analysis uses a conceptual framework based on the interaction between school autonomy, student assessment, and accountability as elements of a closed system. The article analyzes the implementation of school autonomy and accountability policy, using data collected from 226 schools in Thailand that participated in the 2009 PISA survey. To understand how autonomy and accountability relate to student achievement, the study estimates a linear regression with PISA reading achievement as the dependent variable and indicators of autonomy and accountability (and control variables) as the independent variables. The estimates suggest that students at schools exercising a higher level of operational autonomy than the level ascribed by regulation tend to have PISA reading scores 6.0-8.6 points higher than students at schools that behave less autonomously. These results are consistent with other research findings. [ABSTRACT FROM AUTHOR]

Surface plasmon polaritons, propagating bound oscillations of electrons and light at a metal surface, have great potential as information carriers for next-generation, highly integrated nanophotonic devices. Since the term ‘active plasmonics’ was coined in 2004, a number of techniques for controlling the propagation of guided surface plasmon polariton signals have been demonstrated. However, with sub-microsecond or nanosecond response times at best, these techniques are likely to be too slow for future applications in such fields as data transport and processing. Here we report that femtosecond optical frequency plasmon pulses can propagate along a metal–dielectric waveguide and that they can be modulated on the femtosecond timescale by direct ultrafast optical excitation of the metal, thereby offering unprecedented terahertz modulation bandwidth—a speed at least five orders of magnitude faster than existing technologies. [ABSTRACT FROM AUTHOR]

Averageness is purportedly the result of stabilizing selection maintaining the population mean, whereas facial paedomorphosis is a product of directional selection driving the population mean towards an increasingly juvenile appearance. If selection is predominantly stabilizing, intermediate phenotypes reflect high genetic quality and mathematically average faces should be found attractive. If, on the other hand, directional selection is strong enough, extreme phenotypes reflect high genetic quality and juvenilized faces will be found attractive. To compare the effects of stabilizing and directional selection on facial paedomorphosis (juvenilization), graphic morphing and editing techniques were used to alter the appearance of composite faces to make them appear more or less juvenile. Both facial models and judges of attractiveness were from the CSU-Long Beach campus. Although effect sizes for both preferences were large, the effect for averageness was nearly twice that found for juvenilization, an indication that stabilizing selection influences preferences for facial paedomorphosis more so than directional selection in contemporary humans. [ABSTRACT FROM AUTHOR]

Illustrates the types of contribution than an evolutionary perspective can make to thinking about fertility and its relation to the environment. Life history as a general theoretical framework that incorporates environmental influences, contextual influences and heritable variation; Effects of between-group competition for resources on population issues; Factors that influence political power within and between societies.

Presents a paper which discusses the involvement of the Jews in shaping the United States' immigration policy. Interest of Jews in opposing the establishment of ethnically and culturally homogeneous societies in which they reside as minorities; Types of movements supported by Jews; Reference to essays written by Horace Kallen.

The purpose of this article is to develop a model of life history theory that incorporates environmental influences, contextual influences, and heritable variation. I argue that physically or psychologically stressful environments delay maturation and the onset of reproductive competence. The social context is also important, and here I concentrate on the opportunity for upward social mobility as a contextual influence that results in delaying reproduction and lowering fertility in the interest of increasing investment in children. I also review evidence that variation in life history strategies is influenced by genetic variation as well. Finally, I show that cultural shifts in the social control of sexual behavior have had differential effects on individuals predisposed to high- versus low-investment reproductive strategies. [ABSTRACT FROM AUTHOR]

Physical play is an important vehicle for differential socialization of boys and girls into appropriate sex roles. The aim of the study was to examine developmental changes in patterns of parent-child physical play as a function of the sex of parent and child. Three hundred ninety families with a total of 746 children ranging in age from under 1 year to 10 years were contacted by telephone and questioned about the frequency of physical-play interactions with their children. The results indicated that the strongest variable affecting the frequency of physical play was the age of the child. This developmental effect was curvilinear, with comparatively low levels prior to age one, a peak in the early childhood years, and the decline thereafter. Fathers tended to engage in more physical play than mothers. Effects of child sex were less evident, but tended to indicate that girls participated more often in nonstrenuous physical games with their parents, such as pattycake and being bounced on the parent's knee, while boys participated more often in activities such as wrestling and ball playing. There was a modest but significant tendency for older parents to engage less often in physical play with their children at each age level. The implications of parent-child physical play for sex role typing were noted. [ABSTRACT FROM AUTHOR]

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The article presents an obituary for Dr. Tereba Togola, National director of Cultural Heritage, Mali.