Flexibility in continuous judgments of gender/sex and race.

Across six preregistered studies (N = 1,292; recruited from university subject pools and Prolific Academic), we investigate how face perception along the dimensions of gender/sex and race can vary based on immediate contextual information as well as personal experience. In Studies 1a and 1b, we find that when placing stimuli along a continuum from male to female, cisgender participants sort prototypical gender/sex faces in a bimodal fashion and show less consensus and greater error when placing faces of intermediate gender/sex. We replicate and extend these findings to race in Study 2. In Study 3, we test whether sorting patterns can be influenced by preexisting experiences, and find evidence that transgender/nonbinary participants show less error than cisgender heterosexual participants when sorting intermediary faces. Finally, in Studies 4 and 5, we test whether cisgender participants' judgments of intermediary faces along the continuum are influenced by the specific circumstances under which they are asked to sort. Here, we find that changing the sorting framework to include a third category resulted in less error when placing intermediary faces along the continuum than when participants were provided with only two category labels or two categories and a line at the midpoint, suggesting that new perceptual categories introduced with minimal training can be adopted quickly and successfully in a perceptual task. These data suggest that both long-term life experiences and quick experimental interventions can shape how we think about gender/sex and race. (PsycInfo Database Record (c) 2024 APA, all rights reserved).

Young children interpret number gestures differently than nonsymbolic sets.

Researchers have long been interested in the origins of humans' understanding of symbolic number, focusing primarily on how children learn the meanings of number words (e.g., "one", "two", etc.). However, recent evidence indicates that children learn the meanings of number gestures before learning number words. In the present set of experiments, we ask whether children's early knowledge of number gestures resembles their knowledge of nonsymbolic number. In four experiments, we show that preschool children (n = 139 in total; age M = 4.14 years, SD = 0.71, range = 2.75-6.20) do not view number gestures in the same the way that they view nonsymbolic representations of quantity (i.e., arrays of shapes), which opens the door for the possibility that young children view number gestures as symbolic, as adults and older children do. A video abstract of this article can be viewed at https://youtu.be/WtVziFN1yuI HIGHLIGHTS: Children were more accurate when enumerating briefly-presented number gestures than arrays of shapes, with a shallower decline in accuracy as quantities increased. We replicated this finding with arrays of shapes that were organized into neat, dice-like configurations (compared to the random configurations used in Experiment 1). The advantage in enumerating briefly-presented number gestures was evident before children had learned the cardinal principle. When gestures were digitally altered to pit handshape configuration against number of fingers extended, children overwhelmingly based their responses on handshape configuration.

Functionalised nanopores: chemical and biological modifications.

Nanopore technology has established itself as a powerful tool for single-molecule studies. By analysing changes in the ion current flowing through a single transmembrane channel, a wealth of molecular information can be elucidated. Early studies utilised nanopore technology for sensing applications, and subsequent developments have diversified its remit. Nanopores can be synthetic, solid-state, or biological in origin, but recent work has seen these boundaries blurred as hybrid functionalised pores emerge. The modification of existing pores and the construction of novel synthetic pores has been an enticing goal for creating systems with tailored properties and functionality. Here, we explore chemically functionalised biological pores and the bio-inspired functionalisation of solid-state pores, highlighting how the convergence of these domains provides enhanced functionality.

Parent math anxiety predicts early number talk.

Differences in children's math knowledge emerge as early as the start of kindergarten, and persist throughout schooling. Previous research implicates the importance of early parent number talk in the development of math competency. Yet we understand little about the factors that relate to variation in early parent number talk. The current study examined the relation of parent math anxiety and family socioeconomic status (SES) to parent number talk with children under the age of three (n = 36 dyads). For the first time, we show preliminary evidence that parent math anxiety (MA) predicts the amount of number talk children hear at home, beyond differences accounted for by SES. We also found a significant SES by parent MA interaction such that parent MA was predictive of higher-SES parents' number talk but not that of lower-SES parents. Furthermore, we found that these relations were specific to parents' cardinal number talk (but not counting), which has been shown to be particularly important in children's math development.

Causal Effects of Parent Number Talk on Preschoolers' Number Knowledge.

Individual differences in children's number knowledge arise early and are associated with variation in parents' number talk. However, there exists little experimental evidence of a causal link between parent number talk and children's number knowledge. Parent number talk was manipulated by creating picture books which parents were asked to read with their children every day for 4 weeks. N = 100 two- to four-year olds and their parents were randomly assigned to read either Small Number (1-3), Large Number (4-6), or Control (non-numerical) books. Small Number books were particularly effective in promoting number knowledge relative to the Control books. However, children who began the study further along in their number development also benefited from reading the Large Number Books with their parents.

Switchable foldamer ion channels with antibacterial activity.

Synthetic ion channels may have applications in treating channelopathies and as new classes of antibiotics, particularly if ion flow through the channels can be controlled. Here we describe triazole-capped octameric α-aminoisobutyric acid (Aib) foldamers that "switch on" ion channel activity in phospholipid bilayers upon copper(ii) chloride addition; activity is "switched off" upon copper(ii) extraction. X-ray crystallography showed that CuCl2 complexation gave chloro-bridged foldamer dimers, with hydrogen bonds between dimers producing channels within the crystal structure. These interactions suggest a pathway for foldamer self-assembly into membrane ion channels. The copper(ii)-foldamer complexes showed antibacterial activity against B. megaterium strain DSM319 that was similar to the peptaibol antibiotic alamethicin, but with 90% lower hemolytic activity.

Synthetically Diversified Protein Nanopores: Resolving Click Reaction Mechanisms.

Nanopores are emerging as a powerful tool for the investigation of nanoscale processes at the single-molecule level. Here, we demonstrate the methionine-selective synthetic diversification of α-hemolysin (α-HL) protein nanopores and their exploitation as a platform for investigating reaction mechanisms. A wide range of functionalities, including azides, alkynes, nucleotides, and single-stranded DNA, were incorporated into individual pores in a divergent fashion. The ion currents flowing through the modified pores were used to observe the trajectory of a range of azide-alkyne click reactions and revealed several short-lived intermediates in Cu(I)-catalyzed azide-alkyne [3 + 2] cycloadditions (CuAAC) at the single-molecule level. Analysis of ion-current fluctuations enabled the populations of species involved in rapidly exchanging equilibria to be determined, facilitating the resolution of several transient intermediates in the CuAAC reaction mechanism. The versatile pore-modification chemistry offers a useful approach for enabling future physical organic investigations of reaction mechanisms at the single-molecule level.

Number gestures predict learning of number words.

When asked to explain their solutions to a problem, children often gesture and, at times, these gestures convey information that is different from the information conveyed in speech. Children who produce these gesture-speech "mismatches" on a particular task have been found to profit from instruction on that task. We have recently found that some children produce gesture-speech mismatches when identifying numbers at the cusp of their knowledge, for example, a child incorrectly labels a set of two objects with the word "three" and simultaneously holds up two fingers. These mismatches differ from previously studied mismatches (where the information conveyed in gesture has the potential to be integrated with the information conveyed in speech) in that the gestured response contradicts the spoken response. Here, we ask whether these contradictory number mismatches predict which learners will profit from number-word instruction. We used the Give-a-Number task to measure number knowledge in 47 children (Mage  = 4.1 years, SD = 0.58), and used the What's on this Card task to assess whether children produced gesture-speech mismatches above their knower level. Children who were early in their number learning trajectories ("one-knowers" and "two-knowers") were then randomly assigned, within knower level, to one of two training conditions: a Counting condition in which children practiced counting objects; or an Enriched Number Talk condition containing counting, labeling set sizes, spatial alignment of neighboring sets, and comparison of these sets. Controlling for counting ability, we found that children were more likely to learn the meaning of new number words in the Enriched Number Talk condition than in the Counting condition, but only if they had produced gesture-speech mismatches at pretest. The findings suggest that numerical gesture-speech mismatches are a reliable signal that a child is ready to profit from rich number instruction and provide evidence, for the first time, that cardinal number gestures have a role to play in number-learning.

Meaning before order: Cardinal principle knowledge predicts improvement in understanding the successor principle and exact ordering.

Learning the cardinal principle (the last word reached when counting a set represents the size of the whole set) is a major milestone in early mathematics. But researchers disagree about the relationship between cardinal principle knowledge and other concepts, including how counting implements the successor function (for each number word N representing a cardinal value, the next word in the count list represents the cardinal value N + 1) and exact ordering (cardinal values can be ordered such that each is one more than the value before it and one less than the value after it). No studies have investigated acquisition of the successor principle and exact ordering over time, and in relation to cardinal principle knowledge. An open question thus remains: Is the cardinal principle a "gatekeeper" concept children must acquire before learning about succession and exact ordering, or can these concepts develop separately? Preschoolers (N = 127) who knew the cardinal principle (CP-knowers) or who knew the cardinal meanings of number words up to "three" or "four" (3-4-knowers) completed succession and exact ordering tasks at pretest and posttest. In between, children completed one of two trainings: counting only versus counting, cardinal labeling, and comparison. CP-knowers started out better than 3-4-knowers on succession and exact ordering. Controlling for this disparity, we found that CP-knowers improved over time on succession and exact ordering; 3-4-knowers did not. Improvement did not differ between the two training conditions. We conclude that children can learn the cardinal principle without understanding succession or exact ordering and hypothesize that children must understand the cardinal principle before learning these concepts.

Enzymatically Ligated DNA-Surfactants: Unmasking Hydrophobically Modified DNA for Intracellular Gene Regulation.

Herein, we describe the characterization of a novel self-assembling and intracellular disassembling nanomaterial for nucleic acid delivery and targeted gene knockdown. By using a recently developed nucleic acid nanocapsule (NAN) formed from surfactants and conjugated DNAzyme (DNz) ligands, it is shown that DNz-NAN can enable cellular uptake of the DNAzyme and result in 60 % knockdown of a target gene without the use of transfection agents. The DNAzyme also exhibits activity without chemical modification, which we attribute to the underlying nanocapsule design and release of hydrophobically modified nucleic acids as a result of enzymatically triggered disassembly of the NAN. Fluorescence-based experiments indicate that the surfactant-conjugated DNAzymes are better able to access a fluorescent mRNA target within a mock lipid bilayer system than the free DNAzyme, highlighting the advantage of the hydrophobic surfactant modification to the nucleic acid ligands. In vitro characterization of DNz-NAN's substrate-cleavage kinetics, stability in biological serum, and persistence of knockdown against a proinflammatory transcription factor, GATA-3, are presented.

Resilience in mathematics after early brain injury: The roles of parental input and early plasticity.

Children with early focal unilateral brain injury show remarkable plasticity in language development. However, little is known about how early brain injury influences mathematical learning. Here, we examine early number understanding, comparing cardinal number knowledge of typically developing children (TD) and children with pre- and perinatal lesions (BI) between 42 and 50 months of age. We also examine how this knowledge relates to the number words children hear from their primary caregivers early in life. We find that children with BI, are, on average, slightly behind TD children in both cardinal number knowledge and later mathematical performance, and show slightly slower learning rates than TD children in cardinal number knowledge during the preschool years. We also find that parents' "number talk" to their toddlers predicts later mathematical ability for both TD children and children with BI. These findings suggest a relatively optimistic story in which neural plasticity is at play in children's mathematical development following early brain injury. Further, the effects of early number input suggest that intervening to enrich the number talk that children with BI hear during the preschool years could narrow the math achievement gap.

Nucleic Acid Nanocapsules for Enzyme-Triggered Drug Release.

Herein we describe a nucleic acid functionalized nanocapsule in which nucleic acid ligands are assembled and disassembled in the presence of enzymes. The particles are fully degradable in response to esterases due to an embedded ester cross-linker in the particle's core. During synthesis the nanocapsules can be loaded with hydrophobic small molecules and post self-assembly undergo covalent cross-linking using copper catalyzed click chemistry. They can then be functionalized with thiolated DNA through stepwise thiolyne chemistry using UV light irradiation. Additionally, the capsule is compatible with enzyme mediated functionalization of a therapeutic mRNA-cleaving DNAzyme at the particle's surface. The resulting particle is highly stable, monodisperse in size, and maximizes the therapeutic potential of both the particles interior and exterior.

Gesture as a window onto children's number knowledge.

Before learning the cardinal principle (knowing that the last word reached when counting a set represents the size of the whole set), children do not use number words accurately to label most set sizes. However, it remains unclear whether this difficulty reflects a general inability to conceptualize and communicate about number, or a specific problem with number words. We hypothesized that children's gestures might reflect knowledge of number concepts that they cannot yet express in speech, particularly for numbers they do not use accurately in speech (numbers above their knower-level). Number gestures are iconic in the sense that they are item-based (i.e., each finger maps onto one item in a set) and therefore may be easier to map onto sets of objects than number words, whose forms do not map transparently onto the number of items in a set and, in this sense, are arbitrary. In addition, learners in transition with respect to a concept often produce gestures that convey different information than the accompanying speech. We examined the number words and gestures 3- to 5-year-olds used to label small set sizes exactly (1-4) and larger set sizes approximately (5-10). Children who had not yet learned the cardinal principle were more than twice as accurate when labeling sets of 2 and 3 items with gestures than with words, particularly if the values were above their knower-level. They were also better at approximating set sizes 5-10 with gestures than with words. Further, gesture was more accurate when it differed from the accompanying speech (i.e., a gesture-speech mismatch). These results show that children convey numerical information in gesture that they cannot yet convey in speech, and raise the possibility that number gestures play a functional role in children's development of number concepts.

The effects of word-learning biases on children's concept of angle.

Despite evidence that young children are sensitive to differences in angle measure, older students frequently struggle to grasp this important mathematical concept. When making judgments about the size of angles, children often rely on erroneous dimensions such as the length of the angles' sides. The present study tested the possibility that this misconception stems from the whole-object word-learning bias by providing a subset of children with a separate label to refer to the whole angle figure. Thirty preschoolers (M = 4.86 years, SD = .53) were tested with a pretest-training-posttest design. At pretest, children showed evidence of the whole-object misconception. After training, children who were given a novel-word label for the whole object improved significantly more than those trained on the meaning of "angle" alone.