494 research outputs found
Effects of frequency and idiomaticity on second language reading comprehension in children with English as an additional language
Vocabulary plays an important role in reading comprehension in both the L1 and the L2 (Murphy, 2018). In measuring vocabulary knowledge, however, researchers typically focus on mono-lexical units where vocabulary assessments tend not to take into account multi-word expressions which include phrasal verbs, collocations, and idioms. Omitting these multi-word lexical items can lead to an over-estimation of comprehension skills, particularly in reading. Indeed, adult learners of English comprehend texts containing a larger number of multi-word expressions less well compared to texts containing fewer of these expressions, even when the same words are used in each text (Martinez & Murphy, 2011). To investigate whether children learning English as an additional language (EAL) face a similar challenge, two reading comprehension tests were administered to EAL and monolingual (non-EAL) English-speaking children in primary school. Both tests contained the same common words, but whereas in one test some of the words occurred in multi-word expressions, in the other test they did not. Reading comprehension was significantly reduced for both groups of children when multi-word expressions were included. Monolingual participants generally performed better than children with EAL on both tests further suggesting that children with EAL may face a particular disadvantage in English reading comprehension. These results are discussed within the context of the importance of developing rich vocabulary knowledge in all children, and especially emergent bilingual children, within primary school and beyond
Cross linguistic influence in adult L2/L3 learners: The case of French on English Morphosyntax
Abstract—The potential ways in which learning a second or third language can influence other languages in the mind of the (emergent) bilingual is an increasingly important issue given the international importance of foreign language learning. This study explored whether learning French as a foreign language influences knowledge of English morphosyntax in learners of L2 French with L1 English (n=21) and learners of L3 French with L2 English (n=9). Comparing these two groups allowed us to identify whether and to what extent backwards cross linguistic influence (CLI) are different depending on whether French is L2 or L3, and whether English is L1 or L2. Accuracy on tense-aspects of English morphosyntax was measured through two tasks (Grammaticality Judgement and Proofreading). Results indicated no inhibitive influence from L2 French to L1 English, with potential enhancement of explicit knowledge when compared to a control group of English-speaking participants with no French. In contrast, influence leading to inaccuracy was observed from L3 French to L2 English in that the L3 French learners made more errors in past simple and present perfect in the GJT. Results are discussed in the context of better understanding the nature of developing grammatical systems, together with implications for future work
The Effects of Completing PREP Academy: A University-Based Transition Project for Students with Disabilities (Practice Brief)
This practice brief provides an overview of a project designed to support students with disabilities considering postsecondary education. Postsecondary Rewarding Education is Possible (PREP) Academy was developed by individuals from a state vocational rehabilitation agency and a public research university. PREP Academy is a campus-based, weeklong experience in which students participate in activities designed to mirror the “college experience.” In an evaluation of the project’s second year, a total of 23 students and six parents/guardians completed a pre- and post-survey to examine how attending the project affected students’ perceptions related to students attending college. Interview data from three student and parent/guardian pairs were collected to further explore students’ perceptions and to learn what components of the project were most beneficial. Results provided evidence both students and parents/guardians believe students are better prepared to attend college after participating. An emerging theme related to increasing the project’s emphasis on mirroring aspects of college was identified
Complementary network-based approaches for exploring genetic structure and functional connectivity in two vulnerable, endemic ground squirrels
The persistence of small populations is influenced by genetic structure and functional connectivity. We used two network-based approaches to understand the persistence of the northern Idaho ground squirrel (Urocitellus brunneus) and the southern Idaho ground squirrel (U. endemicus), two congeners of conservation concern. These graph theoretic approaches are conventionally applied to social or transportation networks, but here are used to study population persistence and connectivity. Population graph analyses revealed that local extinction rapidly reduced connectivity for the southern species, while connectivity for the northern species could be maintained following local extinction. Results from gravity models complemented those of population graph analyses, and indicated that potential vegetation productivity and topography drove connectivity in the northern species. For the southern species, development (roads) and small-scale topography reduced connectivity, while greater potential vegetation productivity increased connectivity. Taken together, the results of the two network-based methods (population graph analyses and gravity models) suggest the need for increased conservation action for the southern species, and that management efforts have been effective at maintaining habitat quality throughout the current range of the northern species. To prevent further declines, we encourage the continuation of management efforts for the northern species, whereas conservation of the southern species requires active management and additional measures to curtail habitat fragmentation. Our combination of population graph analyses and gravity models can inform conservation strategies of other species exhibiting patchy distributions
MitoNeoD:a mitochondria-targeted superoxide probe
Mitochondrial superoxide (O2⋅−) underlies much oxidative damage and redox signaling. Fluorescent probes can detect O2⋅−, but are of limited applicability in vivo, while in cells their usefulness is constrained by side reactions and DNA intercalation. To overcome these limitations, we developed a dual-purpose mitochondrial O2⋅− probe, MitoNeoD, which can assess O2⋅− changes in vivo by mass spectrometry and in vitro by fluorescence. MitoNeoD comprises a O2⋅−-sensitive reduced phenanthridinium moiety modified to prevent DNA intercalation, as well as a carbon-deuterium bond to enhance its selectivity for O2⋅− over non-specific oxidation, and a triphenylphosphonium lipophilic cation moiety leading to the rapid accumulation within mitochondria. We demonstrated that MitoNeoD was a versatile and robust probe to assess changes in mitochondrial O2⋅− from isolated mitochondria to animal models, thus offering a way to examine the many roles of mitochondrial O2⋅−production in health and disease
The Kepler Smear Campaign: Light curves for 102 Very Bright Stars
We present the first data release of the Kepler Smear Campaign, using
collateral 'smear' data obtained in the Kepler four-year mission to reconstruct
light curves of 102 stars too bright to have been otherwise targeted. We
describe the pipeline developed to extract and calibrate these light curves,
and show that we attain photometric precision comparable to stars analyzed by
the standard pipeline in the nominal Kepler mission. In this paper, aside from
publishing the light curves of these stars, we focus on 66 red giants for which
we detect solar-like oscillations, characterizing 33 of these in detail with
spectroscopic chemical abundances and asteroseismic masses as benchmark stars.
We also classify the whole sample, finding nearly all to be variable, with
classical pulsations and binary effects. All source code, light curves, TRES
spectra, and asteroseismic and stellar parameters are publicly available as a
Kepler legacy sample.Comment: 35 pages, accepted ApJ
Using exomarkers to assess mitochondrial reactive species in vivo
Background:
The ability to measure the concentrations of small damaging and signalling molecules such as reactive oxygen species (ROS) in vivo is essential to understanding their biological roles. While a range of methods can be applied to in vitro systems, measuring the levels and relative changes in reactive species in vivo is challenging.
Scope of review:
One approach towards achieving this goal is the use of exomarkers. In this, exogenous probe compounds are administered to the intact organism and are then transformed by the reactive molecules in vivo to produce a diagnostic exomarker. The exomarker and the precursor probe can be analysed ex vivo to infer the identity and amounts of the reactive species present in vivo. This is akin to the measurement of biomarkers produced by the interaction of reactive species with endogenous biomolecules.
Major conclusions and general significance:
Our laboratories have developed mitochondria-targeted probes that generate exomarkers that can be analysed ex vivo by mass spectrometry to assess levels of reactive species within mitochondria in vivo. We have used one of these compounds, MitoB, to infer the levels of mitochondrial hydrogen peroxide within flies and mice. Here we describe the development of MitoB and expand on this example to discuss how better probes and exomarkers can be developed. This article is part of a Special Issue entitled Current methods to study reactive oxygen species - pros and cons and biophysics of membrane proteins. Guest Editor: Christine Winterbourn.
Abbreviations:
EPR, electron paramagnetic resonance; GFP, green fluorescent protein; 4-HNE, 4-hydroxynonenal; MitoB, 3-(dihydroxyboronyl)benzyltriphenylphosphonium bromide; MitoP, (3-hydroxybenzyl)triphenylphosphonium bromide; ROS, reactive oxygen species; SOD, superoxide dismutase; TPMP, methyltriphenylphosphonium; TPP, triphenylphosphonium catio
Acute surgical wound-dressing procedure: Description of the steps involved in the development and validation of an observational metric
The aim of this study was to develop an observational metric that could be used to assess the performance of a practitioner in completing an acute surgical wound-dressing procedure using aseptic non-touch technique (ANTT). A team of clinicians, academics, and researchers came together to develop an observational metric using an iterative six-stage process, culminating in a Delphi panel meeting. A scoping review of the literature provided a background empirical perspective relating to wound-dressing procedure performance. Video recordings of acute surgical wound-dressing procedures performed by nurses in clinical (n = 11) and simulated (n = 3) settings were viewed repeatedly and were iteratively deconstructed by the metric development group. This facilitated the identification of the discrete component steps, potential errors, and sentinel (serious) errors, which characterise a wound dressing procedure and formed part of the observational metric. The ANTT wound-dressing observational metric was stress tested for clarity, the ability to be scored, and interrater reliability, calculated during a further phase of video analysis. The metric was then subjected to a process of cyclical evaluation by a Delphi panel (n = 21) to obtain face and content validity of the metric. The Delphi panel deliberation verified the face and content validity of the metric. The final metric has three phases, 31 individual steps, 18 errors, and 27 sentinel errors. The metric is a tool that identifies the standard to be attained in the performance of acute surgical wound dressings. It can be used as both an adjunct to an educational programme and as a tool to assess a practitioner's performance of a wound-dressing procedure in both simulated and clinical practice contexts
Assessing antibody decline after chemotherapy of early chronic Chagas disease patients
Background: Chagas disease remains a significant public health problem in Latin America. There are only two chemotherapy drugs, nifurtimox and benznidazole, and both may have severe side effects. After complete chemotherapy of acute cases, seropositive diagnosis may revert to negative. However, there are no definitive parasitological or serological biomarkers of cure. Methods: Following a pilot study with seven Bolivian migrants to Spain, we tested 71 serum samples from chronic patients (mean age 12.6 years) inhabiting the Argentine Chaco region. Benznidazole chemotherapy (5–8 mg/kg day, twice daily for 60 days) was administered during 2011–2016. Subsequently, pre-and post-chemotherapy serum samples were analysed in pairs by IgG1 and IgG ELISA using two different antigens and Chagas Sero K-SeT rapid diagnostic tests (RDT). Molecular diagnosis by kDNA-PCR was applied to post-treatment samples. Results: Pilot data demonstrated IgG1 antibody decline in three of seven patients from Bolivia 1 year post-treatment. All Argentine patients in 2017 (averaging 5 years post-treatment), except one, were positive by conventional serology. All were kDNA-PCR-negative. Most (91.5%) pre-treatment samples were positive by the Chagas Sero K-SeT RDT, confirming the predominance of TcII/V/VI. IgG1 and IgG of Argentine patients showed significant decline in antibody titres post-chemotherapy, with either lysate (IgG, P = 0.0001, IgG1, P = 0.0001) or TcII/V/VI peptide antigen (IgG, P = 0.0001, IgG1, P = 0.0001). IgG1 decline was more discriminative than IgG. Antibody decline after treatment was also detected by the RDT. Incomplete treatment was associated with high IgG1 post-treatment titres against lysate (P = 0.013), as were IgG post-treatment titres to TcII/V/VI peptide (P = 0.0001). High pre-treatment IgG1 with lysate was associated with Qom ethnicity (P = 0.045). No associations were found between gender, age, body mass index and pre- or post-treatment antibody titres. Conclusions: We show that following chemotherapy of early chronic Chagas disease, significant decline in IgG1 antibody suggests cure, whereas sustained or increased IgG1 is a potential indicator of treatment failure. Due to restricted sensitivity, IgG1 should not be used as a diagnostic marker but has promise, with further development, as a biomarker of cure. Graphical abstract: We show that following chemotherapy of early chronic Chagas disease, a significant decline in IgG1 antibody suggests cure, whereas sustained or increased IgG1 is a potential indicator of treatment failure. Due to restricted sensitivity, IgG1 should not be used as a diagnostic marker but has promise, with further development, as a biomarker of cure.Fil: Murphy, Niamh. University of London; Reino UnidoFil: Cardinal, Marta Victoria. Universidad de Buenos Aires. Facultad de Ciencias Exactas y Naturales. Departamento de Ecología, Genética y Evolución. Laboratorio de Eco-Epidemiología; Argentina. Consejo Nacional de Investigaciones Científicas y Técnicas. Oficina de Coordinación Administrativa Ciudad Universitaria. Instituto de Ecología, Genética y Evolución de Buenos Aires. Universidad de Buenos Aires. Facultad de Ciencias Exactas y Naturales. Instituto de Ecología, Genética y Evolución de Buenos Aires; ArgentinaFil: Bhattacharyya, Tapan. University of London; Reino UnidoFil: Enriquez, Gustavo Fabián. Consejo Nacional de Investigaciones Científicas y Técnicas. Oficina de Coordinación Administrativa Ciudad Universitaria. Instituto de Ecología, Genética y Evolución de Buenos Aires. Universidad de Buenos Aires. Facultad de Ciencias Exactas y Naturales. Instituto de Ecología, Genética y Evolución de Buenos Aires; ArgentinaFil: Macchiaverna, Natalia Paula. Consejo Nacional de Investigaciones Científicas y Técnicas. Oficina de Coordinación Administrativa Ciudad Universitaria. Instituto de Ecología, Genética y Evolución de Buenos Aires. Universidad de Buenos Aires. Facultad de Ciencias Exactas y Naturales. Instituto de Ecología, Genética y Evolución de Buenos Aires; ArgentinaFil: Alvedro, Alejandra. Consejo Nacional de Investigaciones Científicas y Técnicas. Oficina de Coordinación Administrativa Ciudad Universitaria. Instituto de Ecología, Genética y Evolución de Buenos Aires. Universidad de Buenos Aires. Facultad de Ciencias Exactas y Naturales. Instituto de Ecología, Genética y Evolución de Buenos Aires; ArgentinaFil: Freilij, Héctor. Gobierno de la Ciudad de Buenos Aires. Hospital General de Niños "Ricardo Gutiérrez"; ArgentinaFil: Martinez de Salazar, Pablo. Barcelona Institute For Global Health; EspañaFil: Molina, Israel. Barcelona Institute For Global Health; EspañaFil: Mertens, Pascal. No especifíca;Fil: Gilleman, Quentin. No especifíca;Fil: Gurtler, Ricardo Esteban. Consejo Nacional de Investigaciones Científicas y Técnicas. Oficina de Coordinación Administrativa Ciudad Universitaria. Instituto de Ecología, Genética y Evolución de Buenos Aires. Universidad de Buenos Aires. Facultad de Ciencias Exactas y Naturales. Instituto de Ecología, Genética y Evolución de Buenos Aires; ArgentinaFil: Miles, Michael A.. University of London; Reino Unid
Identification and quantification of protein S-nitrosation by nitrite in the mouse heart during ischemia.
Nitrate (NO3-) and nitrite (NO2-) are known to be cardioprotective and to alter energy metabolism in vivo NO3- action results from its conversion to NO2- by salivary bacteria, but the mechanism(s) by which NO2- affects metabolism remains obscure. NO2- may act by S-nitrosating protein thiols, thereby altering protein activity. But how this occurs, and the functional importance of S-nitrosation sites across the mammalian proteome, remain largely uncharacterized. Here we analyzed protein thiols within mouse hearts in vivo using quantitative proteomics to determine S-nitrosation site occupancy. We extended the thiol-redox proteomic technique, isotope-coded affinity tag labeling, to quantify the extent of NO2--dependent S-nitrosation of proteins thiols in vivo Using this approach, called SNOxICAT (S-nitrosothiol redox isotope-coded affinity tag), we found that exposure to NO2- under normoxic conditions or exposure to ischemia alone results in minimal S-nitrosation of protein thiols. However, exposure to NO2- in conjunction with ischemia led to extensive S-nitrosation of protein thiols across all cellular compartments. Several mitochondrial protein thiols exposed to the mitochondrial matrix were selectively S-nitrosated under these conditions, potentially contributing to the beneficial effects of NO2- on mitochondrial metabolism. The permeability of the mitochondrial inner membrane to HNO2, but not to NO2-, combined with the lack of S-nitrosation during anoxia alone or by NO2- during normoxia places constraints on how S-nitrosation occurs in vivo and on its mechanisms of cardioprotection and modulation of energy metabolism. Quantifying S-nitrosated protein thiols now allows determination of modified cysteines across the proteome and identification of those most likely responsible for the functional consequences of NO2- exposure
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