821 research outputs found
Crossing MGLS with the Middle Grades Research Agenda: A Guide for Researchers
For the past several years, leaders in middle grades education research have strengthened their call for more methodologically robust quantitative research to address important questions in the field. Recently, two important routes towards addressing this call have emerged: the Middle Grades Longitudinal Study from the National Center for Education Statistics, and a new research agenda from the Middle Level Education Research Special Interest Group of the American Educational Research Association. In this paper, we conduct a content analysis of the items in the forthcoming longitudinal study in light of the extant research agenda. Results indicate that research questions in eight sections of the agenda are moderately to well-addressed by the data, and that the longitudinal study will provide rich contextual data related to many others. The concurrent emergence of the research agenda and this data offers an opportunity for the research community to engage in high-level quantitative research with a middle grades lens to inform future policy. The item-by-item crosswalk available for download (scroll down for link below) provides guidance for researchers using the Middle Grades Longitudinal Study data to address questions from the research agenda
Machining and grinding of ultrahigh-strength steels and stainless steel alloys
Machining and grinding of ultrahigh-strength steels and stainless steel alloy
1,3,4,6-Tetramethyl-1,4-dihydro-1,2,4,5-tetrazine, C_6H_(12)N_4
M_r =140∙19, monoclinic, P2_1/n, a = 10∙612(3), b=6∙820(1), c= 10∙975 (2) Å, β=95∙31(2)°, V=790.9(5) Å^3, Z=4, D_m=1.13(5) (flotation), D_x = 1∙177 g cm^(-3), Mo Kα, λ = 0.71073 Å, μ= 0.848 cm^(-1), F(000) = 304, T= 295 K, R = 0∙077 for 704 observed reflections. This potentially antiaromatic or homoaromatic ring system has a flattened boat conformation with both N-methyls in equatorial positions. Bond angles and distances (excluding H's) predicted to be symmetry equivalent exhibit variations of 0.002-0.014 Å and 0.0-2.0°. Substantial delocalization of the electron lone pairs of N(1) and N(4) is found
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Urban storage heat flux variability explored using satellite, meteorological and geodata
The storage heat flux (ΔQS) is the net flow of heat stored within a volume that may include the air, trees, buildings and ground. Given the difficulty of measurement of this important and large flux in urban areas, we explore the use of Earth Observation (EO) data. EO surface temperatures are used with ground-based meteorological forcing, urban morphology, land cover and land use information to estimate spatial variations of ΔQS in urban areas using the Element Surface Temperature Method (ESTM). First, we evaluate ESTM for four “simpler” surfaces. These have good agreement with observed values. ESTM coupled to SUEWS (an urban land surface model) is applied to three European cities (Basel, Heraklion, London), allowing EO data to enhance the exploration of the spatial variability in ΔQS. The impervious surfaces (paved and buildings) contribute most to ΔQS. Building wall area seems to explain variation of ΔQS most consistently. As the paved fraction increases up to 0.4, there is a clear increase in ΔQS. With a larger paved fraction, the fraction of buildings and wall area is lower which reduces the high values of ΔQS
Deep-Learning for Classification of Colorectal Polyps on Whole-Slide Images
Histopathological characterization of colorectal polyps is an important
principle for determining the risk of colorectal cancer and future rates of
surveillance for patients. This characterization is time-intensive, requires
years of specialized training, and suffers from significant inter-observer and
intra-observer variability. In this work, we built an automatic
image-understanding method that can accurately classify different types of
colorectal polyps in whole-slide histology images to help pathologists with
histopathological characterization and diagnosis of colorectal polyps. The
proposed image-understanding method is based on deep-learning techniques, which
rely on numerous levels of abstraction for data representation and have shown
state-of-the-art results for various image analysis tasks. Our
image-understanding method covers all five polyp types (hyperplastic polyp,
sessile serrated polyp, traditional serrated adenoma, tubular adenoma, and
tubulovillous/villous adenoma) that are included in the US multi-society task
force guidelines for colorectal cancer risk assessment and surveillance, and
encompasses the most common occurrences of colorectal polyps. Our evaluation on
239 independent test samples shows our proposed method can identify the types
of colorectal polyps in whole-slide images with a high efficacy (accuracy:
93.0%, precision: 89.7%, recall: 88.3%, F1 score: 88.8%). The presented method
in this paper can reduce the cognitive burden on pathologists and improve their
accuracy and efficiency in histopathological characterization of colorectal
polyps, and in subsequent risk assessment and follow-up recommendations
PCR detection and analyzis of potentially zoonotic Hepatitis E virus in French rats
BACKGROUND: Hepatitis E virus has been detected in a wide range of animals. While Genotypes 1-2 of this virus infect only humans, 3-4 can spread from animals to humans and cause sporadic cases of human disease. Pig, and possibly also rats, may act as a reservoir for virus. From a public health perspective it is important to clarify the role of rats for infection of humans. Rats often live close to humans and are therefore of special interest to public health. Rats live of waste and inside the sewage system and may become infected. Reports of hepatitis E virus in rats have been published but not from France. The possibility that rats in an urban area in France were Hepatitis E virus infected, with which type and relationship to other strains was investigated. This study provides information important to public health and better understanding the occurrence of hepatitis E virus in the environment. Eighty one rats (Rattus Norvegicus) were captured, euthanized, sampled (liver and faeces) and analyzed by real-time RT-PCR’s, one specific for Hepatitis E virus in rats and one specific for genotype 1-4 that that is known to infect humans. Positive samples were analyzed by a nested broad spectrum RT-PCR, sequenced and compared with sequences in Genbank. FINDINGS: Twelve liver and 11 faeces samples out of 81 liver and 81 faeces samples from 81 captured rats were positive in the PCR specific for Hepatitis E virus in rats and none in the PCR specific for genotype 1-4. Comparison by nucleotide BLAST showed a maximum of 87% similarity to Hepatitis E virus previously detected in rats and significantly less to genotype 1-4. CONCLUSIONS: This is the first study demonstrating that rats in France carries hepatitis E virus and provide information regarding its relation to other virus strains previously detected in rats and other host animals world-wide. Genotype 1-4 was not detected
Stereochemical studies on protonated bridgehead amines. ^1H NMR determination of cis and trans B-C ring-fused structures for salts of hexahydropyrrolo [2,1-a] isoquinolines and related C ring homologs. Capture of unstable ring-fused structures in the solid state
Acid-addition salts of tricyclic isoquinolines 2a/b, 3a/b, 4a-4c, 5, 6a/b, 7, 8a/b, 9a/b, and 17a/b were studied by high-field ^1H NMR in CDCl_3 solution. Cis (e.g., 14 and 15 in Figure 1) and trans (e.g., 13)B-C ring-fused structures were identified by using the vicinal ^3J(CH-NH) coupling constants, which demonstrate a Karplus-like behavior. In some cases, we initially observed a trans form, which converted to a cis A form by N H proton exchange. For 4c.HBr, the exchange process was slowed by addition of trifluoroacetic acid. In many cases, cis A and cis B structures were preferred in solution. The pendant phenyl group exerted a strong influence on the preferred solution structure. Observation of the initial, unstable trans-fused structures was related to their capture in the solid state and release intact on dissolution. X-ray diffraction was performed on the HBr salts of 2a (B-C cis), 2b (B-C cis), and 4c (B-C trans). The result for 4c.HBr confirmed the connection between the initial trans form in solution and the solid state. For 17b.HCI two conformers, associated with hindered rotation about the bond connecting the 2,6-disubstituted phenyl group to the tricyclic array, were detected at ambient probe temperature; however, rotamers were not observed for either of the two forms (trans and cis A) of 17a.HBr. Two conformers were also found for 16b.HBr. Temperature-dependent behavior was recorded in the ^1H NMR spectra of 17b.HBr and 16b.HBr; the activation free energy for interconversion of conformers was estimated to be in the vicinity of 17 kcal/mol for the former and 14-15 kcal/mol for the latter. The ^1H NMR spectrum of butaclamol hydrochloride (20.HC1), a potent neuroleptic agent, in Me_2SO-d_6 revealed two species in a ratio of 81:19, which were assigned as trans and cis A forms, respectively. ^1H NMR data for various free bases are also presented and discussed. Empirical force field calculations on three model hydrocarbons are discussed from a perspective of finding an explanation for the configurational/conformational behavior of the bridgehead ammonium salts. Diverse literature examples of structures for protonated bridgehead amines are also discussed. A tentative rationale is suggested for the preference of cis A forms in some protonated tetrahydroisoquinoline derivatives
Increasing Student Creativity And Connection To Nature Through Equitable Nature-based Experiences During Middle School Distance Learning
This paper seeks to answer the question: How can middle school teachers increase student creativity and connection to nature through equitable nature-based experiences during distance learning? This paper reviews the history of nature based learning (NBL) and exploratory learning, and examines the positive outcomes of these practices. These benefits include increased engagement and interest in normally uninterested students (Dettweiler et al., 2015; Truong et al., 2016), improved grades (Camassao & Jagannathan, 2018), and reduced disruptive episodes and dropouts among “at risk” students (Ruiz-Gallardo et al., 2013 as cited in Kuo et al., 2019). Although many research studies have shown positive physical, social, emotional and academic benefits of NBL (Kuo et al., 2019), there are glaring equity issues in terms of representation and access to outdoor spaces based on gender (Clark, 2015), race (Finney, 2014), and socioeconomic status (Astell-Burt, 2014). A new equity issue arose when schools moved to distance learning models in response to the COVID 19 pandemic. This seven week digital nature journal curriculum addresses the need for creativity and connection to nature during distance learning for all students regardless of their background, prior experiences or access to outdoor space. By engaging each student through observation, inquiry and creation, this project will help to build a more connected, passionate and creative generation of student advocates that is desperately needed in our ever changing world
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