Social affiliation motives modulate spontaneous learning in Williams syndrome but not in autism

BACKGROUND: Children with autism spectrum disorder (ASD) and those with Williams syndrome (WS) have difficulties with learning, though the nature of these remains unclear. METHODS: In this study, we used novel eye-tracking and behavioral paradigms to measure how 36 preschoolers with ASD and 21 age- and IQ-matched peers with WS attend to and learn novel behaviors (1) from the outcomes of their own actions (non-social learning), (2) through imitation of others’ actions (social learning), and across situations in which imitative learning served either an instrumental function or fulfilled social affiliation motives. RESULTS: The two groups demonstrated similar abilities to learn from the consequences of their own actions and to imitate new actions that were instrumental to the achievement of a tangible goal. Children with WS, unlike those with ASD, increased their attention and imitative learning performance when the model acted in a socially engaging manner. CONCLUSIONS: Learning abnormalities in ASD appear to be linked to the social rather than instrumental dimensions of learning

Verbal labels increase the salience of novel objects for preschoolers with typical development and Williams syndrome, but not in autism

Background: Early research has documented that young children show an increased interest toward objects that are verbally labeled by an adult, compared to objects that are presented without a label. It is unclear whether the same phenomenon occurs in neurodevelopmental disorders affecting social development, such as autism spectrum disorder (ASD) and Williams syndrome (WS). Methods: The present study used a novel eye-tracking paradigm to determine whether hearing a verbal label increases the salience of novel objects in 35 preschoolers with ASD, 18 preschoolers with WS, and 20 typically developing peers. Results: We found that typically developing children and those with WS, but not those with ASD, spent significantly more time looking at objects that are verbally labeled by an adult, compared to objects that are presented without a label. Conclusions: In children without ASD, information accompanied by the speaker's verbal label is accorded a "special status," and it is more likely to be attended to. In contrast, children with ASD do not appear to attribute a special salience to labeled objects compared to non-labeled objects. This result is consistent with the notion that reduced responsivity to pedagogical cues hinders social learning in young children with ASD

Aptamer-functionalized nanopipettes : a promising approach for viral fragment detection via ion current rectification

In this report, ion current rectification, an electrochemical phenomenon observed in asymmetric nanopipettes, is used for the label-free detection of SARS-CoV-2 viral fragments in nasopharyngeal samples. Quartz nanopipettes are functionalized with aptamers targeting the spike protein S1 domain, wherein changes to the surface charge magnitude, distribution, and ion transport behavior modulate the current-voltage response upon binding. The aptamer-modified nanopipette provides a selective and sensitive method for detecting SARS-CoV-2, with a limit of detection in the laboratory of 0.05 pg/mL. The effectiveness of this low-cost platform was demonstrated by sensing SARS-CoV-2 in nasopharyngeal samples, successfully discriminating between positive and negative cases with minimal template preparation, highlighting the platform’s potential as a versatile sensing strategy for infectious disease detection in clinical diagnosis

Dopamine transporter genotype is associated with a lateralized resistance to distraction during attention selection

Although lateral asymmetries in orienting behavior are evident across species and have been linked to interhemispheric asymmetries in dopamine signaling, the relative contribution of attentional versus motoric processes remains unclear. Here we took a cognitive genetic approach to adjudicate between roles for dopamine in attentional versus response selection. A sample of nonclinical adult humans (N = 518) performed three cognitive tasks (spatial attentional competition, spatial cueing, and flanker tasks) that varied in the degree to which they required participants to resolve attentional or response competition. All participants were genotyped for two putatively functional tandem repeat polymorphisms of the dopamine transporter gene (DAT1; SLC6A3), which are argued to influence the level of available synaptic dopamine and confer risk to disorders of inattention. DAT1 genotype modulated the task-specific effects of the various task-irrelevant stimuli across both the spatial competition and spatial cueing but not flanker tasks. Specifically, compared with individuals carrying one or two copies of the 10-repeat DAT1 allele, individuals without this allele demonstrated an immunity to distraction, such that response times were unaffected by increases in the number of distractor stimuli, particularly when these were presented predominantly in the left hemifield. All three genotype groups exhibited uniform costs of resolving leftward response selection in a standard flanker task. None of these significant effects could be explained by speed–accuracy trade-offs, suggesting that participants without the 10-repeat allele of the DAT1 tandem repeat polymorphism possess an enhanced attentional ability to suppress task-irrelevant stimuli in the left hemifield

Stable C, O, and S isotope record of magmatic-hydrothermal interactions between the Falémé Fe Skarn and the Loulo Au Systems in Western Mali

Abstract The Gara, Yalea, and Gounkoto Au deposits of the >17 Moz Loulo mining district, largely hosted by the Kofi series metasediments, are located several kilometers to the east of the 650-Mt Fe skarn deposits in the adjacent Falémé batholith. The Au deposits are interpreted to have formed through phase separation of an aqueous-carbonic fluid, which locally mixed with a hypersaline brine of metaevaporite origin. Recognition of an intrusive relationship between the Falémé batholith and Kofi series opens the possibility that the Fe skarns and Au deposits are part of the same mineral system. In this paper, we combine new δ13C, δ18O, and δ34S data from the Karakaene Ndi skarn, Au occurrences along the western margin of the Kofi series, and zircons within plutonic rocks of the Falémé batholith. We combine these with existing data from the Loulo Au deposits to model the contribution of magmatic volatiles to Au mineralization. C and O isotope compositions of auriferous carbonate-quartz-sulfide veins from the Loulo Au deposits have wide ranges (δ13C: –21.7 to –4.5‰ and δ18O: 11.8 to 23.2‰), whereas values from carbonate veins in Kofi series Au prospects close to the Falémé batholith and the Karakaene Ndi Fe skarn deposit have more restricted ranges (δ13C: –16.8 to –3.7‰, δ18O: 11.4 to 17.2‰, and δ13C: –3.0 ± 1‰, δ18O: 12.6 ± 1‰, respectively). Kofi series dolostones have generally higher isotopic values (δ13C: –3.1 to 1.3‰ and δ18O: 19.1 to 23.3‰). Pyrite from Kofi series Au prospects adjacent to the Falémé batholith have a wide range of δ34S values (–4.6 to 14.2‰), similar to pyrite from the Karakaene Ndi skarn (2.8 to 11.9‰), whereas δ34S values of pyrite and arsenopyrite from the Loulo deposits are consistently >6‰. Comparison of the C and O isotope data with water-rock reaction models indicates the Loulo Au deposits formed primarily through unmixing of an aqueous carbonic fluid derived from the devolatilization of sedimentary rocks with an organic carbon component. Isotopic data are permissive of the hypersaline brine that enhanced this phase separation including components derived from both Kofi series evaporite horizons interlayered with the dolostones and a magmatic-hydrothermal brine. This magmatic-hydrothermal component is particularly apparent in O, C, and S isotope data from the Gara deposit and Au prospects immediately adjacent to the Falémé batholith

Microwave Imaging for Neoadjuvant Chemotherapy Monitoring: Initial Clinical Experience

Introduction: Microwave tomography recovers images of tissue dielectric properties, which appear to be specific for breast cancer, with low-cost technology that does not present an exposure risk, suggesting the modality may be a good candidate for monitoring neoadjuvant chemotherapy. Methods: Eight patients undergoing neoadjuvant chemotherapy for locally advanced breast cancer were imaged longitudinally five to eight times during the course of treatment. At the start of therapy, regions of interest (ROIs) were identified from contrast-enhanced magnetic resonance imaging studies. During subsequent microwave examinations, subjects were positioned with their breasts pendant in a coupling fluid and surrounded by an immersed antenna array. Microwave property values were extracted from the ROIs through an automated procedure and statistical analyses were performed to assess short term (30 days) and longer term (four to six months) dielectric property changes. Results: Two patient cases (one complete and one partial response) are presented in detail and demonstrate changes in microwave properties commensurate with the degree of treatment response observed pathologically. Normalized mean conductivity in ROIs from patients with complete pathological responses was significantly different from that of partial responders (P value = 0.004). In addition, the normalized conductivity measure also correlated well with complete pathological response at 30 days (P value = 0.002). Conclusions: These preliminary findings suggest that both early and late conductivity property changes correlate well with overall treatment response to neoadjuvant therapy in locally advanced breast cancer. This result is consistent with earlier clinical outcomes that lesion conductivity is specific to differentiating breast cancer from benign lesions and normal tissue

The DESI Sky Continuum Monitor System

The Dark Energy Spectroscopic Instrument (DESI) is an ongoing spectroscopic survey to measure the dark energy equation of state to unprecedented precision. We describe the DESI Sky Continuum Monitor System, which tracks the night sky brightness as part of a system that dynamically adjusts the spectroscopic exposure time to produce more uniform data quality and to maximize observing efficiency. The DESI dynamic exposure time calculator (ETC) will combine sky brightness measurements from the Sky Monitor with data from the guider system to calculate the exposure time to achieve uniform signal-to-noise ratio (SNR) in the spectra under various observing conditions. The DESI design includes 20 sky fibers, and these are split between two identical Sky Monitor units to provide redundancy. Each Sky Monitor unit uses an SBIG STXL-6303e CCD camera and supports an eight-position filter wheel. Both units have been completed and delivered to the Mayall Telescope at the Kitt Peak National Observatory. Commissioning results show that the Sky Monitor delivers the required performance necessary for the ETC.Comment: 9 pages, 7 figures, 1 tabl

Sea ice and its effect on CO2 flux between the atmosphere and the Southern Ocean interior

Author Posting. © American Geophysical Union, 2011. This article is posted here by permission of American Geophysical Union for personal use, not for redistribution. The definitive version was published in Journal of Geophysical Research 116 (2011): C11019, doi:10.1029/2010JC006509.The advance and retreat of sea ice produces seasonal convection and stratification, dampens surface waves and creates a separation between the ocean and atmosphere. These are all phenomena that can affect the air-sea gas transfer velocity (k660), and therefore it is not straightforward to determine how sea ice cover modulates air-sea flux. In this study we use field estimates k660 to examine how sea ice affects the net gas flux between the ocean and atmosphere. An inventory of salinity, 3He, and CFC-11 in the mixed layer is used to infer k660 during the drift of Ice Station Weddell in 1992. The average of k660 is 0.11 m d−1 across nearly 100% ice cover. In comparison, the only prior field estimates of k660 are disproportionately larger, with average values of 2.4 m d−1 across 90% sea ice cover, and 3.2 m d−1 across approximately 70% sea ice cover. We use these values to formulate two scenarios for the modulation of k660 by the fraction of sea ice cover in a 1-D transport model for the Southern Ocean seasonal ice zone. Results show the net CO2 flux through sea ice cover represents 14–46% of the net annual air-sea flux, depending on the relationship between sea ice cover and k660. The model also indicates that as much as 68% of net annual CO2 flux in the sea ice zone occurs in the springtime marginal ice zone, which demonstrates the need for accurate parameterizations of gas flux and primary productivity under partially ice-covered conditions.Support for this work was provided by the Climate Center at the Lamont‐Doherty Earth Observatory, an NSF IGERT Fellowship and a NOAA Climate and Global Change Postdoctoral Fellowship to BL, and NSF grant OPP 01‐25523/ANT 04‐40825 (PS).2012-05-1