Taking risks with a growth mindset: long-term influence of an elementary pre-service after school science practicum

In this study, we present the long-term influence of an after school science practicum associated with an elementary science methods course. The practicum or field experience could be considered a community-based service learning programme as it is situated both within and for the community. Study participants included eight third- and fifth-grade teachers who had participated in elementary science methods courses; four of these teachers participated in the after school teaching practicum while four participants experienced a more traditional observation-based elementary science practicum. All of these teachers were in their second or third year teaching which was 3–4 years after taking the methods course. Investigation methods included questionnaires, field observations and semi-structured, individual interviews. Teachers more regularly utilised reform-based teaching strategies and cited the after school teaching practicum as preparing them to use these strategies in their own classrooms. All teachers exhibited a growth mindset to some degree, but the after school practicum participants did demonstrate a wider use of reformed-based teaching strategies and a higher growth mindset. Elementary teachers perceive risk associated with these key aspects of instruction: (1) managing instruction and classroom management, (2) teaching science through guided inquiry, and (3) overcoming adoptions in other ‘mandated’ curriculum like math and reading.     

Anhydrobiosis

In aquatic and moist soil environments subjected to periodic drying, a diverse group of organisms (mostly microscopic) have evolved extreme desiccation tolerance through a physiological adaptation called ‘anhydrobiosis’. Notable among such organisms are tardigrades, bdelloid rotifers, and nematodes. Anhydrobiosis also allows these organisms to tolerate extreme temperatures and ionizing radiation. In this article, the signi-cance and some mechanisms of anhydrobiosis are described.     

Trophic Cascades

In many ecosystems, apex consumers (top predators) play a crucial role in food web dynamics. Their top-down impacts are known to spread downwards through the food webs in a cascading fashion. Trophic cascades manifest when top predators are excluded from an ecosystem or introduced into a system lacking them. Two such case studies are described here. Trophic cascades are generally more pronounced in the aquatic than in the terrestrial ecosystems, which in turn is related to the differences in the average body sizes of herbivores relative to the plant resources they feed upon and in the structure of their food webs. Scientists express concern that human activities have been leading to planet-wide trophic downgrading (loss of apex consumers) which could affect vital ecological processes of the biosphere.     

An intensification approach to double-block algebra: A pilot implementation of Intensified Algebra in a large urban school district

Double-block instruction has become a popular strategy for supporting struggling mathematics students in algebra I. Despite its widespread adoption, little consistent evidence supports the attributes of a successful double-block design or the effectiveness of this instructional strategy. In this study, the authors examine a pilot implementation of a double-block strategy—instantiated in the program Intensified Algebra—that combines core algebra content with insights from research on how students learn mathematics and explicit noncognitive supports focused on key attitudes, beliefs, and behaviors essential to student success. The results of the study show that, when implemented with fidelity, participation in the program significantly increased student achievement on the state end-of-course algebra I assessment.     

Transitioning in higher education: an exploration of psychological and contextual factors affecting student satisfaction

In view of recent changes in the higher education sector, such as increased tuition fees, a greater focus has been placed on widening participation initiatives and monitoring student satisfaction. The aims of the current study were twofold: (1) to explore whether pre-entry programmes foster successful transition to higher education, and (2) to examine longitudinally the factors associated with course satisfaction. Eighty-eight first-year psychology students completed a questionnaire measuring academic self-efficacy, social identity and student satisfaction at the start (Time 1, November 2015) and end (Time 2, March 2016) of the academic year. Findings indicated that students who participated in a pre-entry programme reported higher academic self-efficacy and satisfaction compared to typical route students. Moreover, academic self-efficacy predicted student satisfaction at the start of the academic year, whereas in-group affect (a facet of social identity) predicted this at the end of the academic year. The current findings indicate that pre-entry programmes may have a positive impact on students’ sense of academic self-efficacy. On a more general level, the findings also suggest that academic self-efficacy and social identity may be key indicators of student satisfaction. This highlights the complexities of the concept of ‘student satisfaction’, and demonstrates the utility of examining multiple factors relating to student satisfaction across different time points.     

Exploring the complex and non-linear evolution of Chinese international students’ experiences in US colleges

This article contests the narrative of Chinese international students (internationals for short) as passive and problematic to reveal the complexity and fluidity of their experiences. Simultaneously, it troubles the overly linear approach of stage theory in understanding internationals’ adjustment. Following nine first- and nine second-year students in US colleges over a year and involving them in semi-structured interviews and journal prompts, this research examined how they evolved. Findings show that while participants grew on academic and personal fronts, their experiences remained multi-dimensional, with second years being less sanguine and reporting challenges different from first years. This article argues that seeing Chinese internationals’ evolution as an uneven ascent affords a more nuanced understanding compared to a U-shape stage theory as it recognizes that while internationals are evolving, new situations provide challenges which they learn to overcome. Consequently, Chinese internationals’ growth troubles the deficit discourse around them and departs from pre-existing research around postgraduates. Findings spell implications for how the college community should enhance transcultural understanding and how future research around internationals could develop.     

Impulsive fixed-time observer for linear time-delay systems

This paper presents a fixed-time observer for a general class of linear time-delay systems. In contrast to many existing observers, which normally estimate system’s trajectory in an asymptotic fashion, the proposed observer estimates system’s state in a prescribed time. The proposed fixed-time observer is realized by updating the observer in an impulsive manner. Simulation results are also presented to illustrate the convergence behavior of the proposed fixed-time observer.     

Hierarchical linear dynamical systems for unsupervised musical note recognition

In this paper we develop a new framework for time series segmentation based on a Hierarchical Linear Dynamical System (HLDS), and test its performance on monophonic and polyphonic musical note recognition. The center piece of our approach is the inclusion of constraints in the filter topology, instead of on the cost function as normally done in machine learning. Just by slowing down the dynamics of the top layer of an augmented (multilayer) state model, which is still compatible with the recursive update equation proposed originally by Kalman, the system learns directly from data all the musical notes, without labels, effectively creating a time series clustering algorithm that does not require segmentation. We analyze the HLDS properties and show that it provides better classification accuracy compared to current state-of-the-art approaches.     

Truncation error analysis in computing of SEP and SEP floor for partially coherent receiver of MPSK signals over composite fading channels

In this paper, we analyze detection of multilevel phase-shift keying (MPSK) signals transmitted over a Gamma shadowed Nakagami-m fading channel. We derive novel analytical expression, in terms of Meijer’s G function, for Fourier coefficients of the probability density function of the received signal composite phase. Under the assumption of the imperfect reference signal extraction in the receiver, which is performed from the pilot signal, the analytical expression is derived for the symbol error probability (SEP) in the form of convergent series. The existence of the error floor is identified, and expression for its computation is provided. Mathematical proofs for convergence of Fourier series are provided for both SEP and SEP floor, and novel expressions of upper bounds for truncation errors are derived in terms of elementary mathematical functions. The convergence rate of the derived expressions is examined. Numerical results are confirmed independently by Monte-Carlo simulations.