40 research outputs found
Border Literacies and the Plazas Comunitarias Program
In this column, I hope to contribute to the wider discussion on this topic by highlighting a specific binational adult literacy program called Plazas Comunitarias to illustrate how some adults are developing Spanish literacy on the border and explore to what extent a model like Plazas could act as a bridge to both Spanish and English literacy learning. Among its many features, learners enrolled in Plazas can also work towards earning official certificates for primaria and secundaria (the equivalent to elementary and middle school) issued directly from the Ministry of Education in Mexico. At the same time, I take a look at the ways in which the local organizations that help implement the Plazas program play a role in overall community engagement and have the potential to be a valuable resource for Latinx families on the border and beyond, particularly for those with children enrolled in the school system. Therefore, K-12 educators working with Latinx families may well find programs such as Plazas to be a valuable community resource for parents by opening up avenues to literacy learning that could support both their and their children’s development
Trusting Children: Lifelong Learning And Autonomy Within The Unschooling Movement
The purpose of this article is to explore the concept of autonomy in the context of education and analyse the complex features of unschooling, a particular movement within the home- based education paradigm. This study will aim to link the significance of autonomy and unschooling and place them within the wider discourse of contemporary lifelong learning (LLL) theories. Under the tenets of humanistic education theories that underline self-driven and intrinsic motivations for learning, this article will highlight the unschooling movement as an example of a subaltern pedagogical approach that is deeply rooted in institutional and ideological autonomy. More importantly, this study intends to challenge the way LLL is conceptualised and propel the international discourse surrounding it beyond the boundaries of institutional education
Optimal filter systems for photometric redshift estimation
In the next years, several cosmological surveys will rely on imaging data to
estimate the redshift of galaxies, using traditional filter systems with 4-5
optical broad bands; narrower filters improve the spectral resolution, but
strongly reduce the total system throughput. We explore how photometric
redshift performance depends on the number of filters n_f, characterizing the
survey depth through the fraction of galaxies with unambiguous redshift
estimates. For a combination of total exposure time and telescope imaging area
of 270 hrs m^2, 4-5 filter systems perform significantly worse, both in
completeness depth and precision, than systems with n_f >= 8 filters. Our
results suggest that for low n_f, the color-redshift degeneracies overwhelm the
improvements in photometric depth, and that even at higher n_f, the effective
photometric redshift depth decreases much more slowly with filter width than
naively expected from the reduction in S/N. Adding near-IR observations
improves the performance of low n_f systems, but still the system which
maximizes the photometric redshift completeness is formed by 9 filters with
logarithmically increasing bandwidth (constant resolution) and half-band
overlap, reaching ~0.7 mag deeper, with 10% better redshift precision, than 4-5
filter systems. A system with 20 constant-width, non-overlapping filters
reaches only ~0.1 mag shallower than 4-5 filter systems, but has a precision
almost 3 times better, dz = 0.014(1+z) vs. dz = 0.042(1+z). We briefly discuss
a practical implementation of such a photometric system: the ALHAMBRA survey.Comment: 4 pages, 4 figures, to appear in The Astrophysical Journal Letter
Teaching Story without Struggle: Using Graded Readers and Their Audio Packs in the EFL Classroom
In recent years the support for extensive reading (ER) in English as a second or foreign language (ESL/EFL) programs has been compelling. When practicing extensive
reading, the learner reads a wide variety of texts for pleasure and achieves a general understanding of the content while deciphering unknown words through context. This approach contrasts with intensive reading, a more
traditional approach based on a slow, careful reading of a text, with goals of complete comprehension and the
identification of specific details and information
A Software Tool to Model Genetic Regulatory Networks. Applications to the Modeling of Threshold Phenomena and of Spatial Patterning in Drosophila
We present a general methodology in order to build mathematical models of genetic regulatory networks. This approach is based on the mass action law and on the Jacob and Monod operon model. The mathematical models are built symbolically by the Mathematica software package GeneticNetworks. This package accepts as input the interaction graphs of the transcriptional activators and repressors of a biological process and, as output, gives the mathematical model in the form of a system of ordinary differential equations. All the relevant biological parameters are chosen automatically by the software. Within this framework, we show that concentration dependent threshold effects in biology emerge from the catalytic properties of genes and its associated conservation laws. We apply this methodology to the segment patterning in Drosophila early development and we calibrate the genetic transcriptional network responsible for the patterning of the gap gene proteins Hunchback and Knirps, along the antero-posterior axis of the Drosophila embryo. In this approach, the zygotically produced proteins Hunchback and Knirps do not diffuse along the antero-posterior axis of the embryo of Drosophila, developing a spatial pattern due to concentration dependent thresholds. This shows that patterning at the gap genes stage can be explained by the concentration gradients along the embryo of the transcriptional regulators
Effect of Therapeutic Hypothermia Initiated After 6 Hours of Age on Death or Disability Among Newborns With Hypoxic-Ischemic Encephalopathy: A Randomized Clinical Trial
Importance:
Hypothermia initiated at less than 6 hours after birth reduces death or disability for infants with hypoxic-ischemic encephalopathy at 36 weeks' or later gestation. To our knowledge, hypothermia trials have not been performed in infants presenting after 6 hours.
Objective:
To estimate the probability that hypothermia initiated at 6 to 24 hours after birth reduces the risk of death or disability at 18 months among infants with hypoxic-ischemic encephalopathy.
Design, Setting, and Participants:
A randomized clinical trial was conducted between April 2008 and June 2016 among infants at 36 weeks' or later gestation with moderate or severe hypoxic-ischemic encephalopathy enrolled at 6 to 24 hours after birth. Twenty-one US Neonatal Research Network centers participated. Bayesian analyses were prespecified given the anticipated limited sample size.
Interventions:
Targeted esophageal temperature was used in 168 infants. Eighty-three hypothermic infants were maintained at 33.5°C (acceptable range, 33°C-34°C) for 96 hours and then rewarmed. Eighty-five noncooled infants were maintained at 37.0°C (acceptable range, 36.5°C-37.3°C).
Main Outcomes and Measures:
The composite of death or disability (moderate or severe) at 18 to 22 months adjusted for level of encephalopathy and age at randomization.
Results:
Hypothermic and noncooled infants were term (mean [SD], 39 [2] and 39 [1] weeks' gestation, respectively), and 47 of 83 (57%) and 55 of 85 (65%) were male, respectively. Both groups were acidemic at birth, predominantly transferred to the treating center with moderate encephalopathy, and were randomized at a mean (SD) of 16 (5) and 15 (5) hours for hypothermic and noncooled groups, respectively. The primary outcome occurred in 19 of 78 hypothermic infants (24.4%) and 22 of 79 noncooled infants (27.9%) (absolute difference, 3.5%; 95% CI, -1% to 17%). Bayesian analysis using a neutral prior indicated a 76% posterior probability of reduced death or disability with hypothermia relative to the noncooled group (adjusted posterior risk ratio, 0.86; 95% credible interval, 0.58-1.29). The probability that death or disability in cooled infants was at least 1%, 2%, or 3% less than noncooled infants was 71%, 64%, and 56%, respectively.
Conclusions and Relevance:
Among term infants with hypoxic-ischemic encephalopathy, hypothermia initiated at 6 to 24 hours after birth compared with noncooling resulted in a 76% probability of any reduction in death or disability, and a 64% probability of at least 2% less death or disability at 18 to 22 months. Hypothermia initiated at 6 to 24 hours after birth may have benefit but there is uncertainty in its effectiveness
Galaxy bias from galaxy–galaxy lensing in the DES science verification data
We present a measurement of galaxy–galaxy lensing around a magnitude-limited (iAB < 22.5) sample of galaxies from the dark energy survey science verification (DES-SV) data. We split these lenses into three photometric-redshift bins from 0.2 to 0.8, and determine the product of the galaxy bias b and cross-correlation coefficient between the galaxy and dark matter overdensity fields r in each bin, using scales above 4 h−1 Mpc comoving, where we find the linear bias model to be valid given our current uncertainties. We compare our galaxy bias results from galaxy–galaxy lensing with those obtained from galaxy clustering and CMB lensing for the same sample of galaxies, and find our measurements to be in good agreement with those in Crocce et al., while, in the lowest redshift bin (z ∼ 0.3), they show some tension with the findings in Giannantonio et al. We measure b· r to be 0.87 ± 0.11, 1.12 ± 0.16 and 1.24 ± 0.23, respectively, for the three redshift bins of width Δz = 0.2 in the range 0.2 < z < 0.8, defined with the photometric-redshift algorithm BPZ. Using a different code to split the lens sample, TPZ, leads to changes in the measured biases at the 10–20 per cent level, but it does not alter the main conclusion of this work: when comparing with Crocce et al. we do not find strong evidence for a cross-correlation parameter significantly below one in this galaxy sample, except possibly at the lowest redshift bin (z ∼ 0.3), where we find r = 0.71 ± 0.11 when using TPZ, and 0.83 ± 0.12 with BPZ
An ISOCAM survey through gravitationally lensing galaxy clusters III : new results from mid-infrared observations of the cluster Abell 2219
The massive cluster of galaxies Abell 2219 (z = 0.228) with two spectacular gravitational lensing arcs was observed at 14.3 μm (hereafter 15 μm) with the Infrared Space Observatory and results were published by Barvainis et al. (\cite{1999AJ....118..645B}). These observations have been reanalysed using a method specifically designed for the detection of faint sources that had been applied to other clusters. Five new sources were detected and the resulting cumulative total of ten sources all have optical counterparts. The mid-infrared sources are identified with three cluster members, three foreground galaxies, an Extremely Red Object, a star and two galaxies of unknown redshift. The spectral energy distributions (SEDs) of the galaxies are fit with models from a selection, using the program GRASIL. Best-fits are obtained, in general, with models of galaxies with ongoing star formation. Infrared luminosities and star formation rates are obtained for six sources: the cluster members and the foreground galaxies. For the three cluster members the infrared luminosities derived from the model SEDs are between ˜5.7 × 1010 L⊙ and 1.4 × 1011 L⊙, corresponding to infrared star formation rates between 10 and 24 M⊙ yr-1. The two cluster galaxies that have optical classifications are in the Butcher-Oemler region of the color-magnitude diagramme. The three foreground galaxies have infrared luminosities between 1.5 × 1010 L⊙ and 9.4 × 1010 L⊙ yielding infrared star formation rates between 3 and 16 M⊙ yr-1. Two of the foreground galaxies are located in two foreground galaxy enhancements (Boschin et al. \cite{2004A&A...416..839B}). Including Abell 2219, six distant clusters of galaxies have been mapped with ISOCAM and luminous infrared galaxies (LIRGs) have been found in three of them. The presence of LIRGs in Abell 2219 strengthens the association between luminous infrared galaxies in clusters and recent or ongoing cluster merger activity. Based on observations with ISO, an ESA project with instruments funded by ESA Member States (especially the PI countries: France, Germany, the Netherlands and the UK) and with the participation of ISAS and NASA
Metagenome-scale analysis yields insights into the structure and function of microbial communities in a copper bioleaching heap
Comparative genomics analysis in Prunoideae to identify biologically relevant polymorphisms
Summary
Prunus is an economically important genus with a wide range of physiological and biological variability. Using the peach genome as a reference, sequencing reads from four almond accessions and one sweet cherry cultivar were used for comparative analysis of these three Prunus species. Reference mapping enabled the identification of many biological relevant polymorphisms within the individuals. Examining the depth of the polymorphisms and the overall scaffold coverage, we identified many potentially interesting regions including hundreds of small scaffolds with no coverage from any individual. Non‐sense mutations account for about 70 000 of the 13 million identified single nucleotide polymorphisms (SNPs). Blast2GO analyses on these non‐sense SNPs revealed several interesting results. First, non‐sense SNPs were not evenly distributed across all gene ontology terms. Specifically, in comparison with peach, sweet cherry is found to have non‐sense SNPs in two 1‐aminocyclopropane‐1‐carboxylate synthase (ACS) genes and two 1‐aminocyclopropane‐1‐carboxylate oxidase (ACO) genes. These polymorphisms may be at the root of the nonclimacteric ripening of sweet cherry. A set of candidate genes associated with bitterness in almond were identified by comparing sweet and bitter almond sequences. To the best of our knowledge, this is the first report in plants of non‐sense SNP abundance in a genus being linked to specific GO terms