A Hybrid Achromatic Metalens

Metalenses, ultra-thin optical elements that focus light using subwavelength structures, have been the subject of a number of recent investigations. Compared to their refractive counterparts, metalenses offer reduced size and weight, and new functionality such as polarization control. However, metalenses that correct chromatic aberration also suffer from markedly reduced focusing efficiency. Here we introduce a Hybrid Achromatic Metalens (HAML) that overcomes this trade-off and offers improved focusing efficiency over a broad wavelength range from 1000-1800 nm. HAMLs can be designed by combining recursive ray-tracing and simulated phase libraries rather than computationally intensive global search algorithms. Moreover, HAMLs can be fabricated in low-refractive index materials using multi-photon lithography for customization or using molding for mass production. HAMLs demonstrated diffraction limited performance for numerical apertures of 0.27, 0.11, and 0.06, with average focusing efficiencies greater than 60% and maximum efficiencies up to 80%. A more complex design, the air-spaced HAML, introduces a gap between elements to enable even larger diameters and numerical apertures

Using Prior Knowledge and Student Engagement to Understand Student Performance in an Undergraduate Learning-to-Learn Course

This study examined prior knowledge and student engagement in student performance. Log data were used to explore the distribution of final grades (i.e., weak, good, excellent final grades) occurring in an elective under-graduate course. Previous research has established behavioral and agentic engagement factors contribute to academic achievement (Reeve, 2013). Hierarchical logistic regression using both prior knowledge and log data from the course revealed: (a) the weak-grades group demonstrated less behavioral engagement than the good-grades group, (b) the good-grades group demonstrated less agentic engagement than the excellent-grades group, and (c) models composed of both prior knowledge and engagement measures were more accurate than models composed of only engagement measures. Findings demonstrate students performing at different grade-levels may experience different challenges in their course engagement. This study informs our own instructional strategies and interventions to increase student success in the course and provides recommendations for other instructors to support student success

Development of a micro flow-through cell for high field NMR spectroscopy.

A highly transportable micro flow-through detection cell for nuclear magnetic resonance (NMR) spectroscopy has been designed, fabricated and tested. This flow-through cell allows for the direct coupling between liquid chromatography (LC) and gel permeation chromatography (GPC) resulting in the possibility of hyphenated LC-NMR and GPC-NMR. The advantage of the present flow cell design is that it is independent and unconnected to the detection probe electronics, is compatible with existing commercial high resolution NMR probes, and as such can be easily implemented at any NMR facility. Two different volumes were fabricated corresponding to between {approx}3.8 and 10 {micro}L detection volume. Examples of the performance of the cell on different NMR instruments, and using different NMR detection probes were demonstrated

Face Processing in the Chimpanzee Brain

SummaryHuman face recognition involves highly specialized cognitive and neural processes that enable the recognition of specific individuals [1–5]. Although comparative studies suggest that similar cognitive processes underlie face recognition in chimpanzees and humans ([6–8] and Supplemental Data), it remains unknown whether chimpanzees also show face-selective activity in ventral temporal cortex. This study is the first to examine regional cerebral glucose metabolism with 18F-flurodeoxyglucose positron emission tomography in chimpanzees after they performed computerized tasks matching conspecifics' faces and nonface objects (Supplemental Data). A whole-brain analysis comparing these two tasks in five chimpanzees revealed significant face-selective activity in regions known to comprise the distributed cortical face-processing network in humans, including superior temporal sulcus and orbitofrontal cortex [9–11]. In order to identify regions that were exclusively active during one task, but not the other, we subtracted a resting-state condition from each task and identified the activity exclusive to each. This revealed numerous distinct patches of face-selective activity in the fusiform gyrus that were interspersed within a large expanse of object-selective cortex. This pattern suggests similar object form topography in the ventral temporal cortex of chimpanzees and humans, in which faces may represent a special class of visual stimulus

Shared mechanisms among probiotic taxa: implications for general probiotic claims

Strain-specificity of probiotic effects has been a cornerstone principle of probiotic science for decades. Certainly, some important mechanisms are present in only a few probiotic strains. But scientific advances now reveal commonalities among members of certain taxonomic groups of probiotic microbes. Some clinical benefits likely derive from these shared mechanisms, suggesting that sub-species-specific, speciesspecific or genus-specific probiotic effects exist. Human trials are necessary to confirm specific health benefits. However, a strain that has not been tested in human efficacy trials may meet the minimum definition of the term ‘probiotic’ if it is a member of a well-studied probiotic species expressing underlying core mechanisms and it is delivered at an effective dose

Shared mechanisms among probiotic taxa: implications for general probiotic claims

Strain-specificity of probiotic effects has been a cornerstone principle of probiotic science for decades. Certainly, some important mechanisms are present in only a few probiotic strains. But scientific advances now reveal commonalities among members of certain taxonomic groups of probiotic microbes. Some clinical benefits likely derive from these shared mechanisms, suggesting that sub-species-specific, species specific or genus-specific probiotic effects exist. Human trials are necessary to confirm specific health benefits. However, a strain that has not been tested in human efficacy trials may meet the minimum definition of the term ‘probiotic’ if it is a member of a well-studied probiotic species expressing underlying core mechanisms and it is delivered at an effective dose

Know and grow: A qualitative evaluation of a parent skills training intervention

Objective: This qualitative study examined the experience of parents of children and adolescents with eating disorders after having participated in a skills-based training intervention. Method: Participants were interviewed and transcripts were analysed using inductive thematic analysis. Results: Parent responses were organised around key themes of (1) effectiveness and acceptability of the intervention; (2) interpersonal experience of the group process; and (3) feedback on intervention content. Overall, the program was seen by parents to be highly relevant with direct application to supporting their child in home and hospital environments. Discussion: This study reports on preliminary evidence that skillsbased training is acceptable to parents and improves parent functioning including parent self-efficacy, and reduces psychological distress, anxiety, and burden. The study also demonstrated that the intervention can be delivered in a tertiary paediatric treatment setting and it may become cost-effective method for supporting parents and other carers. Future research is required on treatment efficacy and patient outcomes

Duplication 16p11.2 in a child with infantile seizure disorder

Submicroscopic recurrent 16p11.2 rearrangements are associated with several neurodevelopmental disorders, including autism, mental retardation, and schizophrenia. The common 16p11.2 region includes 24 known genes, of which 22 are expressed in the developing human fetal nervous system. As yet, the mechanisms leading to neurodevelopmental abnormalities and the broader phenotypes associated with deletion or duplication of 16p11.2 have not been clarified. Here we report a child with spastic quadriparesis, refractory infantile seizures, severe global developmental delay, hypotonia, and microcephaly, and a de novo 598 kb 16p11.2 microduplication. Family history is negative for any of these features in parents and immediate family members. Sequencing analyses showed no mutations in DOC2A , QPRT , and SEZ6L2 , genes within the duplicated 16p11.2 region that have been implicated in neuronal function and/or seizure related phenotypes. The child's clinical course is consistent with a rare seizure disorder called malignant migrating partial seizure disorder of infancy, raising the possibility that duplication or disruption of genes in the 16p11.2 interval may contribute to this severe disorder. © 2010 Wiley-Liss, Inc.Peer Reviewedhttp://deepblue.lib.umich.edu/bitstream/2027.42/75769/1/33415_ftp.pd

The Effect of Comb Architecture on Complex Coacervation

Complex coacervation is a widely utilized technique for effecting phase separation, though predictive understanding of molecular-level details remains underdeveloped. Here, we couple coarse-grained Monte Carlo simulations with experimental efforts using a polypeptide-based model system to investigate how a comb-like architecture affects complex coacervation and coacervate stability. Specifically, the phase separation behavior of linear polycation-linear polyanion pairs was compared to that of comb polycation-linear polyanion and comb polycation-comb polyanion pairs. The comb architecture was found to mitigate cooperative interactions between oppositely charged polymers, as no discernible phase separation was observed for comb-comb pairs and complex coacervation of linear-linear pairs yielded stable coacervates at higher salt concentration than linear-comb pairs. This behavior was attributed to differences in counterion release by linear vs. comb polymers during polyeletrolyte complexation. Additionally, the comb polycation formed coacervates with both stereoregular poly(L-glutamate) and racemic poly(D,L-glutamate), whereas the linear polycation formed coacervates only with the racemic polyanion. In contrast, solid precipitates were obtained from mixtures of stereoregular poly(L-lysine) and poly(L-glutamate). Moreover, the formation of coacervates from cationic comb polymers incorporating up to ~90% pendant zwitterionic groups demonstrated the potential for inclusion of comonomers to modulate the hydrophilicity and/or other properties of a coacervate-forming polymer. These results provide the first detailed investigation into the role of polymer architecture on complex coacervation using a chemically and architecturally well-defined model system, and highlight the need for additional research on this topic