Influences on Student Choice and Voice: Agency, Engagement, and Equity

Students at a suburban high school in the American Mountain West have been separated by race, linguistic ability, and socio-economic status for decades, and the research posits that the ways in which students have moved in cohorts throughout past decades has largely determined their academic pathways in high school. The researcher studied eight student perceptions of variable, heterogeneous grouping and democratic pedagogical practices on academic achievement, feelings of self-agency, and engagement in sophomore English Language Arts; two regular placement (non-advanced) sub-groups of Anglo and Latino/a students were included as student participants. Students were interviewed and observed during group work with peers they chose independently, then in assigned, heterogeneous groups. Students were also given several activities that involved curricular choice and choice in workflow, so it was of interest what factors impacted students’ choices in curricula, peers for group work, and approaches to completing academic tasks. Data collection included questionnaire, interview, observation, review of student work, and tracking of assignment completion and grades. Academic achievement, verbal participation, and self-perceived feelings of efficacy, volition, and safety were assessed to determine whether assigned, heterogeneous grouping that involved democratic choice in curricula inspired higher rates of participation, engagement, achievement, and feelings of efficacy

ERK-1 MAP kinase prevents TNF-induced apoptosis through bad phosphorylation and inhibition of bax translocation in HeLa cells

Extracellular signal-regulated kinase (ERK) 1/2 signaling is involved in tumor cell survival through the regulation of Bcl-2 family members. To explore this further and to demonstrate the central role of the mitochondria in the ERK1/2 pathway we used the HeLa cellular model where apoptosis was induced by tumor necrosis factor (TNF) and cycloheximide (CHX). We show that HeLa cells overexpressing ERK-1 displayed resistance to TNF and CHX. HeLa cells overexpressing a kinase-deficient form of ERK-1 (K71R) were more sensitive to TNF and CHX. In the ERK-1 cells, Bad was phosphorylated during TNF + CHX treatment. In the HeLa wt cells and in the K71R clones TNF and CHX decreased Bad phosphorylation. ERK-1 cells treated with TNF and CHX did not release cytochrome c from the mitochondria. By contrast, HeLa wt and K71R clones released cytochrome c. Bax did not translocate to the mitochondria in ERK-1 cells treated with TNF + CHX. Conversely, HeLa wt and K71R clones accumulated Bax in the mitochondria. In the HeLa wt cells and in both ERK-1 transfectants Bid was cleaved and accumulated in the mitochondria. The caspase-8 inhibitor IETD-FMK and the mitochondrial membrane permeabilization inhibitor bongkrekic acid (BK), partially prevented cell death by TNF + CHX. Anisomycin, a c-Jun N-terminal kinases activator, increased TNF-killing. The ERK-1 cells were resistant to TNF and anisomycin, whereas K71R clones resulted more sensitive. Our study demonstrates that in HeLa cells the ERK-1 kinase prevents TNF + CHX apoptosis by regulating the intrinsic mitochondrial pathway through different mechanisms. Inhibition of the intrinsic pathway is sufficient to almost completely prevent cell death. © 2009 Wiley-Liss, Inc

The evolution of frequency distributions: Relating regularization to inductive biases through iterated learning.

Abstract The regularization of linguistic structures by learners has played a key role in arguments for strong innate constraints on language acquisition, and has important implications for language evolution. However, relating the inductive biases of learners to regularization has proven challenging. In this paper we explore how regular linguistic structures can emerge from language evolution by iterated learning, in which one person's linguistic output is used to generate the linguistic input provided to the next person. We use a model of iterated learning with Bayesian agents to show that this process can result in regularization when learners have the appropriate inductive biases. We then present two experiments demonstrating that simulating the process of language evolution in the laboratory can reveal biases towards regularization that might not otherwise be obvious, allowing weak biases to have strong effects. The results of these experiments suggest that people tend to regularize inconsistent word-meaning mappings. Keywords: iterated learning; Bayesian models; frequency distributions; word learning; language acquisition; Languages are passed from one generation of learners to the next via processes of cultural transmission. Such processes introduce linguistic variation, with the generalizations produced by each generation changing the prevalence of linguistic forms. A particular type of change occurs when forms with unpredictable or inconsistent variation become more regular over time. This process occurs in the creolization of pidgin and learning of sign languages from non-native speakers (e.g. Learning a language with any kind of probabilistic variation requires learning a probability distribution from observed frequencies. Over the last couple of decades, a number of studies have accumulated showing that learners are able to extract a variety of statistics from a wide range of linguistic input (see The results outlined in the previous paragraph paint a mixed picture of the inductive biases involved in learning language from inconsistent input. In this paper, we take a novel approach to this problem. First, we outline a Bayesian model that can be used to make different kinds of inductive biases for frequency distributions explicit. We then use this model to characterize the consequences of a process of language evolution by iterated learning 22

Assessing the spatio-temporal spread of COVID-19 via compartmental models with diffusion in Italy, USA, and Brazil

The outbreak of COVID-19 in 2020 has led to a surge in interest in the mathematical modeling of infectious diseases. Such models are usually defined as compartmental models, in which the population under study is divided into compartments based on qualitative characteristics, with different assumptions about the nature and rate of transfer across compartments. Though most commonly formulated as ordinary differential equation (ODE) models, in which the compartments depend only on time, recent works have also focused on partial differential equation (PDE) models, incorporating the variation of an epidemic in space. Such research on PDE models within a Susceptible, Infected, Exposed, Recovered, and Deceased (SEIRD) framework has led to promising results in reproducing COVID-19 contagion dynamics. In this paper, we assess the robustness of this modeling framework by considering different geometries over more extended periods than in other similar studies. We first validate our code by reproducing previously shown results for Lombardy, Italy. We then focus on the U.S. state of Georgia and on the Brazilian state of Rio de Janeiro, one of the most impacted areas in the world. Our results show good agreement with real-world epidemiological data in both time and space for all regions across major areas and across three different continents, suggesting that the modeling approach is both valid and robust.Comment: 23 pages, 19 figure

Directional Receivers for Diffusion-Based Molecular Communications

The particle motion in diffusion-based molecular communication systems is typically modeled by using Brownian processes. In particular, this model is used to characterize the propagation of signal molecules after their release from the transmitter. This motion cannot include directionality in the propagating signal and translates into omnidirectional broadcast communications. In order to make such molecular communications system suitable for supporting communications protocols at the molecular scales, we propose to improve the receiver capabilities by introducing a form of directionality while receiving biological signals. Inspired by the directionality introduced in electromagnetic communications by means of directional antennas, we designed a nanomachine receiver having directionality properties. Our aim is to increase the average concentration of signal molecules, also referred to as carriers, in the area around the receiver surface. In this way, it is possible to increase the signal strength at the receiver. For this purpose, we propose to use a purely reflecting shell to be placed at a configurable distance from the receiver surface. The shape of the shell can be modeled as either a spherical cap or a cylinder with an empty basis. The presence of this surface causes a number of signal molecules to remain trapped in a region close to the receiver surface for a sufficiently long time. In this way, the probability of assimilating additional carriers by the compliant receptors present on the receiver surface increases. By means of an extensive simulation campaign, we identified the most suitable configuration able to provide a significant advantage with respect to those not adopting the proposed solution. The resulting approach can be regarded as an enabler of protocols for diffusive molecular communications taking advantage of directionality properties at the receiver site. It can result in an increased communication range or in improved capabilities of discriminating signals of coexisting molecular communication systems

If it does take a village to raise a child, how should the village do it? Insights from the kids in places initiative

Cross-sector collaborations are some of the strategies used to promote early childhood development and wellbeing. Without these collaborations, key services for families with young children may be missed or even duplicated. By drawing from experiences in Canada and Italy, we share findings from a study that aimed to understand the factors that make cross-sector collaborations (CSC) succeed or fail. Specifically, the study focused on understanding how CSC promoting early child development are created, maintained, and consolidated; and on identifying the social psychological, organizational, and economic aspects of CSC that help or hinder their functioning. Based on qualitative analysis of data gathered from four focus groups and thirteen interviews conducted across seven Canadian and Italian communities, we conclude that the success of CSC depend of a series of factors that transcend context, language and culture

Repercussions of the COVID-19 pandemic on child and adolescent mental health: A matter of concern—A joint statement from EAP and ECPCP

COVID-19 pandemic and the consequent rigid social distancing measures implemented, including school closures, have heavily impacted children's and adolescents' psychosocial wellbeing, and their mental health problems significantly increased. However, child and adolescent mental health were already a serious problem before the Pandemic all over the world. COVID-19 is not just a pandemic, it is a syndemic and mentally or socially disadvantaged children and adolescents are the most affected. Non-Communicable Diseases (NCDs) and previous mental health issues are an additional worsening condition. Even though many countries have responded with decisive efforts to scale-up mental health services, a more integrated and community-based approach to mental health is required. EAP and ECPCP makes recommendations to all the stakeholders to take action to promote, protect and care for the mental health of a generation

Laser system generating 250-mJ bunches of 5-GHz repetition rate, 12-ps pulses.

We report on a high-energy solid-state laser based on a master-oscillator power-amplifier system seeded by a 5-GHz repetition-rate mode-locked oscillator, aimed at the excitation of the dynamic Casimir effect by optically modulating a microwave resonator. Solid-state amplifiers provide up to 250 mJ at 1064 nm in a 500-ns (macro-)pulse envelope containing 12-ps (micro-)pulses, with a macro/micropulse format and energy resembling that of near-infrared free-electron lasers. Efficient second-harmonic conversion allowed synchronous pumping of an optical parametric oscillator, obtaining up to 40 mJ in the range 750-850 nm