Teasing apart explanations of a developmental delay in binding: experimental evidence from the comparison of SLI and Williams syndrome

This study investigates the knowledge of binding in 21 English-speaking children with SLI, aged 6;08-16;05, compared to 21 children with WS, language- and age-matched, and 21 language-matched control children, aged 4-7;10. Our results demonstrate no difficulties in the interpretation of reflexive or personal pronouns in SLI, revealing an intact knowledge of reflexive binding, as well as spared pragmatic functioning. Children with WS however show difficulties with their interpretation of pronouns, accepting the local binding of a pronoun, indicating impaired pragmatics. Not surprisingly, our language-matched typical controls, aged between 4-7;08 (M=5;03), showed a classic pattern of the Apparent Delay of Principle B Effect (ADPBE). In view of reported pragmatic but not memory deficits in WS, we interpret our results as consistent with the pragmatic deficit explanation but not the memory deficit explanation of the ADPBE

Andreev reflection at point contacts with heavy-fermion UBe13 ?

We comment on a recent Letter by Waelti et al. (PRL 84, 5616 (2000)) on 'Spectroscopic evidence for unconventional superconductivity in UBe13'. We show - by using the basic Wexler formula - that it is unlikely to observe Andreev reflection at point contacts between UBe13 and a normal metal. The large superconducting anomalies usually found for those contacts are mainly due to the resistive Maxwell resistance vanishing below Tc of UBe13.Comment: 1 page, no figures, RevTeX, submitted to Phys. Rev. Let

Designing Amends for Lawful Civilian Casualties

In January 2015, a U.S.-initiated drone strike in Pakistan accidentally killed U.S. citizen Warren Weinstein and Italian aid worker Giovanni Lo Porto. President Obama compensated the families and gave a long speech in which he indicated that he want[ed] to express our grief and condolences to the families of two hostages. The President justified his declassification and disclosure of this strike because the [] families deserved to know the truth. He also offered the following mea culpa: As President and as Commander-in-Chief, I take full responsibility for all our counterterrorism operations . . . . I profoundly regret what happened. On behalf of the United States Government, I offer our deepest apologies

Monte Carlo simulation method for Laughlin-like states in a disk geometry

We discuss an alternative accurate Monte Carlo method to calculate the ground-state energy and related quantities for Laughlin states of the fractional quantum Hall effect in a disk geometry. This alternative approach allows us to obtain accurate bulk regime (thermodynamic limit) values for various quantities from Monte Carlo simulations with a small number of particles (much smaller than that needed with standard Monte Carlo approaches).Comment: 13 pages, 6 figures, 2 table

Environmental and genetic influences on neurocognitive development: the importance of multiple methodologies and time-dependent intervention

Genetic mutations and environmental factors dynamically influence gene expression and developmental trajectories at the neural, cognitive, and behavioral levels. The examples in this article cover different periods of neurocognitive development—early childhood, adolescence, and adulthood—and focus on studies in which researchers have used a variety of methodologies to illustrate the early effects of socioeconomic status and stress on brain function, as well as how allelic differences explain why some individuals respond to intervention and others do not. These studies highlight how similar behaviors can be driven by different underlying neural processes and show how a neurocomputational model of early development can account for neurodevelopmental syndromes, such as autism spectrum disorders, with novel implications for intervention. Finally, these studies illustrate the importance of the timing of environmental and genetic factors on development, consistent with our view that phenotypes are emergent, not predetermined

Modeling the functional genomics of autism using human neurons.

Human neural progenitors from a variety of sources present new opportunities to model aspects of human neuropsychiatric disease in vitro. Such in vitro models provide the advantages of a human genetic background combined with rapid and easy manipulation, making them highly useful adjuncts to animal models. Here, we examined whether a human neuronal culture system could be utilized to assess the transcriptional program involved in human neural differentiation and to model some of the molecular features of a neurodevelopmental disorder, such as autism. Primary normal human neuronal progenitors (NHNPs) were differentiated into a post-mitotic neuronal state through addition of specific growth factors and whole-genome gene expression was examined throughout a time course of neuronal differentiation. After 4 weeks of differentiation, a significant number of genes associated with autism spectrum disorders (ASDs) are either induced or repressed. This includes the ASD susceptibility gene neurexin 1, which showed a distinct pattern from neurexin 3 in vitro, and which we validated in vivo in fetal human brain. Using weighted gene co-expression network analysis, we visualized the network structure of transcriptional regulation, demonstrating via this unbiased analysis that a significant number of ASD candidate genes are coordinately regulated during the differentiation process. As NHNPs are genetically tractable and manipulable, they can be used to study both the effects of mutations in multiple ASD candidate genes on neuronal differentiation and gene expression in combination with the effects of potential therapeutic molecules. These data also provide a step towards better understanding of the signaling pathways disrupted in ASD

Neutral Collective Excitations in Striped Hall States

In the striped Hall state, a magnetic translation in one direction is spontaneously broken to the discrete translation. The spectrum of the neutral collective excitation is obtained in the single mode approximation at half-filled third and fourth Landau levels. The spectrum is anisotropic and has a multiple line node structure. In one direction, the spectrum resembles the liquid Helium spectrum with the phonon and roton minimum.Comment: 2 pages, 2 figures, LT23 Hiroshim