Predicting mathematics achievement from subdomains of early number competence: Differences by grade and achievement level.

This study investigated the relative importance of three subdomains of early number competence (number, number relations, and number operations) in predicting later mathematics achievement in cross-sequential samples of pre-kindergarten (pre-K), kindergarten, and first-grade children (n = 150 at each grade). Ordinary least-squares (OLS) regression analyses showed that each subdomain predicted mathematics achievement at each grade level, controlling for the other two subdomains as well as background variables. All the subdomains explained a significant amount of variance in later mathematics achievement. Unconditional quantile regression analyses examined relations between number competencies and mathematics achievement at quantiles representing low (0.2), intermediate (0.5) and high (0.8) achievement. The subdomain of number operations was highly related to mathematics achievement for high achievers. For low achievers, future mathematics achievement was most highly related to number and number relations abilities in the pre-K sample and to number relations abilities in the kindergarten and first-grade samples. Findings highlight the unique importance of all three subdomains of early number competence for later mathematics achievement, but they show that some of the relations are contingent on achievement level.

Novel polyamide amidine anthraquinone platinum(II) complexes: cytotoxicity, cellular accumulation, and fluorescence distributions in 2D and 3D cell culture models.

1- and 1,5-Aminoalkylamine substituted anthraquinones (AAQs, 1C3 and 1,5C3) were peptide coupled to 1-, 2-, and 3-pyrrole lexitropsins to generate compounds that incorporated both DNA minor groove and intercalating moieties. The corresponding platinum(II) amidine complexes were synthesized through a synthetically facile amine-to-platinum mediated nitrile 'Click' reaction. The precursors as well as the corresponding platinum(II) complexes were biologically evaluated in 2D monolayer cells and 3D tumour cell models. Despite having cellular accumulation levels that were up to five-fold lower than that of cisplatin, the platinum complexes had cytotoxicities that were only three-fold lower. Accumulation was lowest for the complexes with two or three pyrrole groups, but the latter was the most active of the complexes exceeding the activity of cisplatin in the MDA-MB-231 cell line. All compounds showed moderate to good penetration into spheroids of DLD-1 cells with the distributions being consistent with active uptake of the pyrrole containing complexes in regions of the spheroids starved of nutrients.

Dimensionality of Preschoolers' Informal Mathematical Abilities.

Recent research examining children's early mathematical abilities has focused primarily on number and operations (e.g., counting, addition) with considerably less attention directed to the role of other possible dimensions of early mathematical abilities, such as, measurement, geometry, and patterning. The current study examined the dimensionality of informal mathematical abilities by conducting categorical confirmatory factor analysis (CCFA) using data from a large sample of preschool children from low-income families (N=1630; Mean age = 4.46 years, SD = .37) using the Child Math Assessment (CMA; Klein & Starkey, 2004). The best fitting model consisted of four factors of Number and Operations, Measurement, Geometry, and Patterning, with the Number and Operations factor explaining common variance in three first-order factors of Numbering, Operations, and Relations. These findings support the view that informal mathematical knowledge is a multi-dimensional construct comprised of each of these separable dimensions. Additionally, a Multiple Indicators Multiple Causes model was used to determine if mathematical ability differed for male and female preschoolers on each of the four factors or on each of the 35 items of the CMA. Results showed no differences for mathematical abilities between males and females at this age. Future research and curricular implications are discussed.

Impacts of a Comprehensive School Readiness Curriculum for Preschool Children at Risk for Educational Difficulties.

This article reports findings from a cluster-randomized study of an integrated literacy- and math-focused preschool curriculum, comparing versions with and without an explicit socioemotional lesson component to a business-as-usual condition. Participants included 110 classroom teachers from randomized classrooms and approximately eight students from each classroom (N = 760) who averaged 4.48 (SD = 0.44) years of age at the start of the school year. There were positive impacts of the two versions of the curriculum on language, phonological awareness, math, and socioemotional outcomes, but there were no added benefits to academic or socioemotional outcomes for the children receiving explicit socioemotional instruction. Results are discussed with relevance to early childhood theory, policy, and goals of closing the school readiness gap.

Profiles of preschoolers' numerical abilities across quantity representations.

Children's early numerical abilities shape their trajectories for math learning throughout schooling, and task quantity representation (e.g., nonsymbolic vs. symbolic) affects their reasoning about numerical concepts. The role of quantity representation in early numerical ability has typically been studied using variable-centered approaches. The present study builds on past work by using latent profile analysis as a person-centered approach to investigate heterogeneity in U.S. preschoolers' (N = 200, Mage = 4 years, 6 months) numerical abilities across nonsymbolic, verbal symbolic, and written symbolic representation types. The aim was to determine whether numerical ability indicators across the three representation types would result in empirically distinct ability profiles and whether preschool ability profile would predict variance on a standardized assessment of math achievement a year later, in kindergarten. We found evidence of four distinct preschool number ability profiles: (a) consistently low; (b) consistently high; (c) intermediate, with an advantage on nonsymbolic items; and (d) intermediate, with an advantage on verbal symbolic items. Although children in the consistently low and consistently high profiles performed reliably lower and higher, respectively, on the assessment of kindergarten math achievement, the two intermediate profiles performed similarly. The results reveal heterogeneity in preschool numerical ability across quantity representations and suggest that proficiency with either nonsymbolic or verbal representations may be a helpful foundation for building future math achievement. (PsycInfo Database Record (c) 2024 APA, all rights reserved).

Facile preparation of mono-, di- and mixed-carboxylato platinum(IV) complexes for versatile anticancer prodrug design.

Facile strategies were developed for the versatile functionalization of platinum(IV) axial sites, allowing for easy accessibility to unsymmetric mono- and mixed-carboxylato, as well as symmetric di-substituted platinum(IV) complexes. The first method involves the direct oxidation and carboxylation of the platinum(II) center using an appropriate peroxide and the carboxylate of choice to firstly yield a monocarboxylato monohydroxido platinum(IV) complex. This platinum(IV) intermediate can undergo further carboxylation to give rise to a mixed-carboxylato platinum(IV) complex. The second method involves the activation of the carboxylate of choice by a common carbodiimide coupling reagent, and its reaction with a dihydroxido platinum(IV) precursor to give the monocarboxylato platinum(IV) complex. Uronium salts can be employed to promote efficient dicarboxylation of the dihydroxido platinum(IV) precursor. Lastly, an axial azide pendant group was demonstrated to be suitable for orthogonal "click" conjugation reactions.

Design and Analytic Features for Reducing Biases in Skill-Building Intervention Impact Forecasts.

Despite policy relevance, longer-term evaluations of educational interventions are relatively rare. A common approach to this problem has been to rely on longitudinal research to determine targets for intervention by looking at the correlation between children's early skills (e.g., preschool numeracy) and medium-term outcomes (e.g., first-grade math achievement). However, this approach has sometimes over-or under-predicted the long-term effects (e.g., 5th-grade math achievement) of successfully improving early math skills. Using a within-study comparison design, we assess various approaches to forecasting medium-term impacts of early math skill-building interventions. The most accurate forecasts were obtained when including comprehensive baseline controls and using a combination of conceptually proximal and distal short-term outcomes (in the nonexperimental longitudinal data). Researchers can use our approach to establish a set of designs and analyses to predict the impacts of their interventions up to two years post-treatment. The approach can also be applied to power analyses, model checking, and theory revisions to understand mechanisms contributing to medium-term outcomes.

Fewer boys born amid covid-19.

The initial stress of the pandemic may have skewed the birth sex ratio in England and Wales, possibly due to uncertainties causing pregnancy losses of male fetuses, finds Alice Klein.

Western Australia delays reopening.

The state has kept a tight lid on covid-19, but experts say there is little use holding out longer.

New Zealand's new battle.

The return of covid-19 to the country after more than 100 days free of infections shows that nobody can relax, reports Alice Klein.

Why we went for full elimination.

The doctor who devised New Zealand's early and extensive coronavirus response tells Alice Klein what inspired his successful strategy.

Drug trials under way.

We'll soon know if covid-19 can be treated with drugs developed for HIV and Ebola, reports Alice Klein.

Who will get ventilators in a covid-19 crisis?

If there is a shortage of breathing machines, doctors and ethicists say priority should go to people with the best chance of recovery, reports Alice Klein.

New Zealand's success.

The country is tantalisingly close to wiping out covid-19. Does that mean life there can go back to normal? Alice Klein reports.

How much bias results if a quasi-experimental design combines local comparison groups, a pretest outcome measure and other covariates?: A within study comparison of preschool effects.

This study uses a within study comparison design (WSC) to conduct a novel test of how much causal bias results when researchers use a nonequivalent comparison group design type (NECGD) that combines: (a) a comparison group local to the treatment group; (b) a pretest measure of the study outcome; and (c) a rich set of 19 other multidimensional covariates. Most prior WSCs have dealt with the bias consequences of only 1 of these, revealing that each routinely reduces bias but does not necessarily eliminate it. Thus, a need exists to identify NECGDs that more robustly eliminate bias. This study is the first to examine how combining the 3 bias-control mechanisms above affects bias. The intervention we examine is a prekindergarten mathematics curriculum, for which a randomized control trial (RCT) produces a positive 1-year math effect. Final bias in the NECGD is assessed as the difference between its impact and that of the RCT when each design has the same intervention, outcome, and estimand. Over the many specifications we explore, NECGD bias is less than .10 standard deviations, indicating that minimal bias results when an NECGD combines all 3 design elements. The factorial design we use in this study also tests the bias associated with seven other NECGD types. Comparing the total pattern of results shows that the minimal bias when all 3 elements are combined is uniquely attributable to the locally chosen comparison group and not the availability of a pretest or other covariates. In actual research practice, it is impossible to predict in advance which design elements will affect bias by how much in any given application. So further research is needed to probe whether the simultaneous use of all three design elements achieves minimal bias dependably across diverse applications and not just in the preschool math context examined here. (PsycInfo Database Record (c) 2020 APA, all rights reserved).

The Sequential Scale-Up of an Evidence-Based Intervention: A Case Study.

Policy makers face dilemmas when choosing a policy, program, or practice to implement. Researchers in education, public health, and other fields have proposed a sequential approach to identifying interventions worthy of broader adoption, involving pilot, efficacy, effectiveness, and scale-up studies. In this article, we examine a scale-up of an early math intervention to the state level, using a cluster randomized controlled trial. The intervention, Pre-K Mathematics, has produced robust positive effects on children's math ability in prior pilot, efficacy, and effectiveness studies. In the current study, we ask if it remains effective at a larger scale in a heterogeneous collection of pre-K programs that plausibly represent all low-income families with a child of pre-K age who live in California. We find that Pre-K Mathematics remains effective at the state level, with positive and statistically significant effects (effect size on the Early Childhood Longitudinal Study, Birth Cohort Mathematics Assessment = .30, p < .01). In addition, we develop a framework of the dimensions of scale-up to explain why effect sizes might decrease as scale increases. Using this framework, we compare the causal estimates from the present study to those from earlier, smaller studies. Consistent with our framework, we find that effect sizes have decreased over time. We conclude with a discussion of the implications of our study for how we think about the external validity of causal relationships.