Impact of model-based science curriculum and instruction on elementary students' explanations for the hydrosphere

Developing scientific literacy about water systems is critical for K-12 students. However, even with opportunities to build knowledge about the hydrosphere in elementary classrooms, early learners may struggle to understand the water cycle (Forbes et al., 2015 ; Gunckel et al., 2012 ; Zangori et al., 2015 ; Zangori et al., 2017 ). Scientific modeling affords opportunities for students to develop representations, make their ideas visible, and generate model-based explanations for complex natural systems like the water cycle. This study describes a comprehensive evaluation of a 5-year, design-based research project focused on the development, implementation, revision, and testing of an enhanced, model-centered version of the Full Option Science System (FOSS) Water (2005) unit in third grade classrooms. Here, we build upon our previous work (Forbes et al., 2015 a; b; Vo et al., 2015 ; Zangori et al., 2015 ; Zangori et al., 2017 ) by conducting a comparative analysis of student outcomes in two sets of classrooms: (1) one implementing the modeling-enhanced version of the FOSS Water unit developed by the research team (n = 6), and 2) another using the standard, unmodified version of the same curricular unit (n = 5). Results demonstrate that teachers in both conditions implemented the two versions of the curriculum with relative fidelity. On average, students exposed to the modeling-enhanced version of the curriculum showed greater gains in their model-based explanations for the hydrosphere. Engagement in scientific modeling allowed students to articulate hydrologic phenomena by (1) identifying various elements that constitute the hydrosphere, (2) describing how these elements influenced the movement of water in the hydrosphere, and (3) demonstrating underlying processes that govern the movement of water in the hydrosphere.     

Sapria Himalayana

Sighting Sapria in the wild is a lifetime experience for a botanist. Because this rare, parasitic flowering plant is one of the lesser known and poorly understood taxa, which is on the brink of extinction. In India, Sapria is only found in the forests of Namdapha National Park in Arunachal Pradesh. In this article, an attempt has been made to document the diversity, distribution, ecology, and conservation need of this valuable plant.     

Graphosyllabic analysis helps adolescent struggling readers read and spell words

Adolescents with word-reading skills below grade level were randomly assigned to one of three conditions. Those receiving interventions practiced reading 100 multisyllabic words, either by analyzing graphosyllabic units in the words or by reading the words as unanalyzed wholes. The third group received no special instruction. Posttests revealed that graphosyllabic instruction helped students to decode novel words, remember how to read words with practice, and remember the spellings of words when compared to controls. In contrast, whole-word instruction yielded no benefit on transfer tasks compared to controls. Effects were observed primarily among adolescents reading at a third-grade-equivalent level and less so at a fourth- and fifth-grade-equivalent level. Results are consistent with a connectionist view of word learning and indicate the importance of providing struggling readers with instruction and practice in how to fully analyze the graphosyllabic constituents of words.     

‘If the child cannot come to the school,then the school must go to the child’: The railway station platform schools in Odisha,India

Despite its constitutional obligation of ensuring universal primary education, the Indian Government has not been able to find a way to educate its 18 million street children. It is widely accepted that the government lacks the capacity – financial, managerial and human resource – to provide meaningful education to those who are left out of the formal education system. Many civil society organisations across India are trying to bridge the gap by educating children living in high-risk settings. One such initiative, the Railway Platform School started by Ruchika, proves that quality bridge or condensed courses are an effective way of encouraging children to access the formal education system. This article argues that the government needs to appreciate and support this kind of innovative initiatives, and also government and other civil society actors needs to operate under a collaborative framework to ensure reach out to children, who have been left out of the Government schooling system.     

The major players in adaptive immunity

Our immune system, by and large, does a fine job in protecting us from opportunistic and infectious microbes, potential carcinogens and allergens. It is therefore crucial to understand the organization of the immune network. This article focuses on some important features and key players involved in adaptive immune response. The first part of the article dealt with the humoral immune response mediated mainly by immunoglobulins produced by the B cells. The second part deals with T cells, the Major Histocompatibility Complex (MHC)-encoded molecules, and Recombination Activating Genes (RAG) responsible for generating diverse B-cell receptors (BCR) and T-cell receptors (TCR). With the advent of newer and smarter infectious agents, it is important to understand the working of the immune network as more research in this area may facilitate the development of better protective strategies.     

A study of spectrin and lipid peroxidation of red blood cell membrane in thalassaemia carrier

The aim of the present work is to understand the lipid peroxidation of RBC membrane and the spectrin protein content of RBC membrane cytoskeleton of thalassaemic carrier state (trait) of β and hemoglobin E variant (HbE). We have measured the hemoglobin (Hb), malondialdehyde (MDA) and spectrin content of RBC membrane of thalassaemic carrier. The spectrin content (α and β band) of both β and HbE carrier was not changed than normal individuals. However, lipid peroxidation of RBC membrane was significantly increased in both β and HbE trait, and Hb level was also decreased in thalassaemic carrier. It may be assumed that oxidative damage by excess lipid peroxidation may have no role on irreversible membrane damage in β thalassaemia and HbE thalassaemia carrier.     

GENI的设计原则(一)分布式需求定义GENI的重心

2006年8月,GEN(I网络创新的全球化环境)公布其项目的设计原则。来自普林斯顿大学、麻省理工大学、华盛顿大学等学校的十二位专家编写了这份报告。该报告阐述了GENI的研究范围、用户的需求、需求的内在压力以及工程设计的原则。报告指出了GENI的价值主张,广泛的部署、多样化可扩展的网络技术集合、对真实用户流量的支持仍是GENI关注的原则和方向。本刊将分两期连载这一报告,从“分布式需求定义GENI的重心”、“解决分布式需求的内在冲突”等两部分,将这一报告与大家共享。     

Is the ‘Idiot's Box’ raising idiocy? Early and middle childhood television watching and child cognitive outcome

There is widespread belief that exposure to television has harmful effects on children's cognitive development. Most studies that point to a negative correlation between hours of television watching and cognitive outcomes, fail to establish causality. Using the National Longitudinal Survey of Youth (NLSY) we study young children between 5 and 10 years of age during late 1990s and early 2000s. We find strong evidence of negative correlations between hours of television watched and cognitive test scores. However, once parent's characteristics and unobserved child characteristics are taken into account these correlations go away. We find that hours of television viewed per se do not have any measurable impact on children's test scores. Our results are robust to different model specifications and instrumental variable estimates. We conclude that despite the conventional wisdom and the ongoing populist movement, proactive policies to reduce children's television exposure are not likely to improve children's cognitive development and academic performance.