888 research outputs found
AN INVESTIGATION OF ELEMENTARY SCHOOL TEACHERSâ CULTURALLY RELEVANT TEACHING PRACTICES IN TWO CULTURES: A COMPARATIVE STUDY IN CHINA AND THE UNITED STATES
Effective teaching is one of the most important factors in student achievement. Throughout the world, there are high expectations for teacher and student performance. Teachers and students need to navigate the demographic and cultural shifts occurring around the world. Teachersâ cultural awareness and knowledge base of culturally relevant teaching practices is critical to their effectiveness. Based on the need to better understand the cultural responsiveness of teachers, this comparative study investigated elementary school teachersâ culturally relevant teaching practices in China and the U.S. through the use of video-cued ethnography. The following findings were revealed from the study: (a) differences in frequency and application of practices; (b) communication of high expectations across cultures; (c) lack of family and community partnership; (d) emphasis on culturally mediated instruction in the U.S.; and (e) ample time for collaboration and reflection in China
Age and sexârelated variability in the presentation of generalized anxiety and depression symptoms
Background: Generalized anxiety and depression are extremely prevalent and debilitating. There is evidence for age and sex variability in symptoms of depression, but despite comorbidity it is unclear whether this extends to anxiety symptomatology. Studies using questionnaire sum scores typically fail to address this phenotypic complexity. Method: We conducted exploratory and confirmatory factor analyses on Generalized Anxiety Disorder (GADâ7) and Patient Health Questionnaire (PHQâ9) items to identify latent factors of anxiety and depression in participants from the Genetic Links to Anxiety and Depression Study (N = 35,637; 16â93 years). We assessed ageâ and sexârelated variability in latent factors and individual symptoms using multiple logistic regression. Results: Four factors of mood, worry, motor, and somatic symptoms were identified (comparative fit index [CFI] = 0.99, TuckerâLewis Index [TLI] = 0.99, root mean square error of approximation [RMSEA] = 0.07, standardized root mean square residuals [SRMR] = 0.04). Symptoms of irritability (odds ratio [OR] = 0.81) were most strongly associated with younger age, and sleep change (OR = 1.14) with older age. Males were more likely to report mood and motor symptoms (p < .001) and females to report somatic symptoms (p < .001). Conclusion: Significant age and sex variability suggest that classic diagnostic criteria reflect the presentation most commonly seen in younger males. This study provides avenues for diagnostic adaptation and factorâspecific interventions
A differential role for the posterior cerebellum in the adaptive control of convergence eye movements
Introduction The vergence oculomotor system possesses two robust adaptive mechanisms; a fast âdynamicâ and a slow âtonicâ system that are both vital for single, clear and comfortable binocular vision. The neural substrates underlying these vergence adaptive mechanisms in humans is unclear. Methods We investigated the role of the posterior cerebellum in convergence adaptation using inhibitory continuous theta-burst repetitive transcranial magnetic stimulation (cTBS) within a double-blind, sham controlled design while eye movements were recorded at 250hz via infrared oculography. Results In a preliminary experiment we validated our stimulation protocols by reproducing results from previous work on saccadic adaptation during the classic double-step adaptive shortening paradigm. Following this, across a series of three separate experiments we observed a clear dissociation in the effect of cTBS on convergence adaptation. Dynamic adaptation was substantially reduced while tonic adaptation was unaffected. Baseline dynamic fusional vergence response were also unaffected by stimulation. Conclusions These results indicate a differential role for the posterior cerebellum in the adaptive control of convergence eye movements and provide initial evidence that repetitive transcranial magnetic stimulation is a viable tool to investigate the neurophysiology of vergence control. The results are discussed in the context of the current models of implicit motor adaptation of vergence and their application to clinical populations and technology design in virtual and augmented head mounted display architectures. Significance statement The cerebellum plays a critical role in the adaptive control of motor systems. Vergence eye movements shift our gaze in depth allowing us to see in 3D and exhibit two distinct adaptive mechanisms that are engaged under a range of conditions including reading, wearing head-mounted displays and using a new spectacle prescription. It is unclear what role the cerebellum plays in these adaptive mechanisms. To answer this, we temporarily disrupted the function of the posterior cerebellum using non-invasive brain stimulation and report impairment of only one adaptive mechanism, providing evidence for neural compartmentalization. The results have implications for vergence control models and applications to comfort and experience studies in head-mounted displays and the rehabilitation of clinical populations exhibiting vergence dysfunctions.National Science and Engineering Research Council of Canada || Canadian Foundation of Innovators || American Academy of Optometry Foundation || Canadian Institutes for Health Research
The Spitzer c2d Survey of Nearby Dense Cores: I: First Direct Detection of the Embedded Source in IRAM 04191+1522
We report the first detections of the Class 0 protostellar source IRAM
04191+1522 at wavelengths shortward of 60 microns with the Spitzer Space
Telescope. We see extended emission in the Spitzer images that suggests the
presence of an outflow cavity in the circumstellar envelope. We combine the
Spitzer observations with existing data to form a complete dataset ranging from
3.6 to 1300 microns and use these data to construct radiative transfer models
of the source. We conclude that the internal luminosity of IRAM 04191+1522,
defined to be the sum of the luminosity from the internal sources (a star and a
disk), is L_int = 0.08 +/- 0.04 L_sun, placing it among the lowest luminosity
protostars known. Though it was discovered before the launch of the Spitzer
Space Telescope, IRAM 04191+1522 falls within a new class of Very Low
Luminosity Objects being discovered by Spitzer. Unlike the two other
well-studied objects in this class, which are associated either with weak,
compact outflows or no outflows at all, IRAM 04191+1522 has a well-defined
molecular outflow with properties consistent with those expected based on
relations derived from higher luminosity (L_int > 1 L_sun) protostars. We
discuss the difficulties in understanding IRAM 04191+1522 in the context of the
standard model of star formation, and suggest a possible explanation for the
very low luminosity of this source.Comment: Accepted for publication in the Astrophysical Journal. 39 pages, 9
figures. See http://peggysue.as.utexas.edu/SIRTF/ for high-resolution figure
Comparison of depression and anxiety symptom networks in reporters and non-reporters of lifetime trauma in two samples of differing severity
Background: Reported trauma is associated with differences in the course and outcomes of depression and anxiety. However, no research has explored the association between reported trauma and patterns of clinically relevant symptoms of both depression and anxiety. Methods: We used network analysis to investigate associations between reported trauma and depression and anxiety symptom interactions in affected individuals from the Genetic Links to Anxiety and Depression (GLAD) Study (n = 17720), and population volunteers from the UK Biobank (n = 11120). Participants with current moderate symptoms of depression or anxiety were grouped into reporters and non-reporters of lifetime trauma. Networks of 16 depression and anxiety symptoms in the two groups were compared using the network comparison test. Results: In the GLAD Study, networks of reporters and non-reporters of lifetime trauma did not differ on any metric. In the UK Biobank, the symptom network of reporters had significantly greater density (7.80) than the network of non-reporters (7.05). Limitations: The data collected in the GLAD Study and the UK Biobank are self-reported with validated or semi-validated questionnaires. Conclusions: Reported lifetime trauma was associated with stronger interactions between symptoms of depression and anxiety in population volunteers. Differences between reporters and non-reporters may not be observed in individuals with severe depression and/or anxiety due to limited variance in the presentation of disorder
Scientists' warning on extreme wildfire risks to water supply
2020 is the year of wildfire records. California experienced its three largest fires early in its fire season. The Pantanal, the largest wetland on the planet, burned over 20% of its surface. More than 18 million hectares of forest and bushland burned during the 2019â2020 fire season in Australia, killing 33 people, destroying nearly 2500 homes, and endangering many endemic species. The direct cost of damages is being counted in dozens of billion dollars, but the indirect costs on waterârelated ecosystem services and benefits could be equally expensive, with impacts lasting for decades. In Australia, the extreme precipitation (â200âmmâday â1 in several locationâ) that interrupted the catastrophic wildfire season triggered a series of watershed effects from headwaters to areas downstream. The increased runoff and erosion from burned areas disrupted water supplies in several locations. These postâfire watershed hazards via source water contamination, flash floods, and mudslides can represent substantial, systemic longâterm risks to drinking water production, aquatic life, and socioâeconomic activity. Scenarios similar to the recent event in Australia are now predicted to unfold in the Western USA. This is a new reality that societies will have to live with as uncharted fire activity, water crises, and widespread human footprint collide allâaround of the world. Therefore, we advocate for a more proactive approach to wildfireâwatershed risk governance in an effort to advance and protect water security. We also argue that there is no easy solution to reducing this risk and that investments in both green (i.e., natural) and grey (i.e., built) infrastructure will be necessary. Further, we propose strategies to combine modern data analytics with existing tools for use by water and land managers worldwide to leverage several decades worth of data and knowledge on postâfire hydrology
Early Pastoral Economies and Herding Transitions in Eastern Eurasia
While classic models for the emergence of pastoral groups in Inner Asia describe mounted, horse-borne herders sweeping across the Eurasian Steppes during the Early or Middle Bronze Age (ca. 3000-1500 BCE), the actual economic basis of many early pastoral societies in the region is poorly characterized. In this paper, we use collagen mass fingerprinting and ancient DNA analysis of some of the first stratified and directly dated archaeofaunal assemblages from Mongolia's early pastoral cultures to undertake species identifications of this rare and highly fragmented material. Our results provide evidence for livestock-based, herding subsistence in Mongolia during the late 3rd and early 2nd millennia BCE. We observe no evidence for dietary exploitation of horses prior to the late Bronze Age, ca. 1200 BCE - at which point horses come to dominate ritual assemblages, play a key role in pastoral diets, and greatly influence pastoral mobility. In combination with the broader archaeofaunal record of Inner Asia, our analysis supports models for widespread changes in herding ecology linked to the innovation of horseback riding in Central Asia in the final 2nd millennium BCE. Such a framework can explain key broad-scale patterns in the movement of people, ideas, and material culture in Eurasian prehistory
Early Pastoral Economies and Herding Transitions in Eastern Eurasia
While classic models for the emergence of pastoral groups in Inner Asia describe mounted, horse-borne herders sweeping across the Eurasian Steppes during the Early or Middle Bronze Age (ca. 3000â1500 BCE), the actual economic basis of many early pastoral societies in the region is poorly characterized. In this paper, we use collagen mass fingerprinting and ancient DNA analysis of some of the first stratified and directly dated archaeofaunal assemblages from Mongoliaâs early pastoral cultures to undertake species identifications of this rare and highly fragmented material. Our results provide evidence for livestock-based, herding subsistence in Mongolia during the late 3rd and early 2nd millennia BCE. We observe no evidence for dietary exploitation of horses prior to the late Bronze Age, ca. 1200 BCE â at which point horses come to dominate ritual assemblages, play a key role in pastoral diets, and greatly influence pastoral mobility. In combination with the broader archaeofaunal record of Inner Asia, our analysis supports models for widespread changes in herding ecology linked to the innovation of horseback riding in Central Asia in the final 2nd millennium BCE. Such a framework can explain key broad-scale patterns in the movement of people, ideas, and material culture in Eurasian prehistory
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