With rapid development inand , the living environment of human being is facing the unprecedented pressures from various types of pollution. Among the different pollutants, cadmium (Cd) is typical for its widespread pollution areas and higher number of suffered produces (eg., and wheat) than the other risky elements. Once the soil is polluted by Cd, it is very difficult to remediate due to time-consuming and high cost of the recovering processes that are beyond imagination of the ordinary people. In the production, improper land use, crop cultivation, farmland and sources of fertilizers and application methods in particular tend to significantly enhance availability of soil Cd and crop uptake, leading to higher probability of polluted agricultural produces. Therefore, it is of great importance to conduct research on the factors that can reduce quantity of soil available Cd and the measures that can control soil Cd availability to safeguard food safety and human .Past research on some of the secondary, micro-and has been conducted both at home and abroad, however, there is lack of systematic studies with comparisons between different secondary, micro-and affecting the availability of soil Cd under the same conditions. Thus, the objectives of this study were to systematically investigate effects of secondary, micro-and on availability of soil Cd and Cd uptake by . The availability of soil Cd and Cd uptake by as affected by different secondary, micro-and beneficial elements were investigated by incubation studies and pot experiments as well, The availability of soil Cd and Cd uptake by rice as effects of water methods and three secondary and microelements were investigated by incubation studies and pot experiments.On the basis of these studies, some optimized fertilizer practices that are effective in controlling Cd availability on the Cd polluted soil were concluded.1. The results of incubation experiments revealed that different fertilizers significantly affected soil pH and Cd availability. As the soil was flooded, soil pH rose rapidly from 6.4 to 7.0, maintained for a period of time and then dropped down to 6.7 at 60d, while the soil Cd availability underwent a reverse change. Ca2+, Mg2+, S, sodium silicate and calcium carbonate were highly effective in reducing amounts of Cd extracted, while the of Zn2+, Cu2+ and Fe3+ significantly increased the extractable Cd. Thus, the authors suggest that when making fertilizer recommendations of secondary, micro-and beneficial elements to the Cd polluted soils in rice growing season, sodium silicate and S bearing materials are most preferred while use of Cu and Zn should be cautious by strictly controlling its rates following recommendations.2. The results of soil pot experiments revealed that folia application of sodium silicate significantly increased rice grain yield, while calcium carbonate, boric acid and sodium silicate incorporated into soil significantly reduced rice grain yield. The chloride forms of magnesium (Mg), zinc (Zn) and iron (Fe) were more favorable to enhance rice grain yield than the sulfate salts of the three elements, while the sulfate forms of calcium (Ca) and cupper (Cu) just behaved in an opposite manner. Among the three secondary elements of Ca, Mg and sulfur (S), Ca enhanced but Mg and S in particular reduced the concentrations and uptake of Cd in grain. In straw, the concentrations and uptake of Cd were minimized by magnesium chloride and S in particular. It was found that Mg retarded transferring Cd from straw to grain, with magnesium chloride more effective than the magnesium sulfate. Among the studied, Zn was most effective in blocking Cd uptake by rice, and followed by Cu, while folia application of the beneficial element of Si as sodium silicate topped the all the treatments in concentrations and uptake of Cd in grain. The treatments of ferrous sulfate, magnesium chloride, cupper chloride, boric acid and borax effectively depressed but the treatments of Zn and folia application of sodium silicate promoted the transfer of Cd from straw to grain, indicating the mechanism of Si blocking Cd uptake by rice was most likely to occur in soil rather than within plant or in the aboveground portions of the plant. It implies that selecting appropriate forms of secondary, micro-and beneficial elements and using proper application methods could effectively reduce Cd uptake by and Cd content in grain in the Cd polluted soil.3. Effects of water management methods and S、Fe、Zn elements in a pot experiment revealed that among the three water management methods, water drained out at maximal tillering stage (drain-out) produced the highest rice yield, and followed by flooding through the rice growing season (flooding) and non-flooding at all (non-flooding). The flooding management significantly reduced Cd concentration and total content, especially in the Zn treatment, in grain compared to the non-flooding management, and effectively inhibited transfer of Cd from rice straw to grain. On contrary, the non-flooding management promoted Cd transfer. Thus, it is suggested that flooding water management should be used all time when possible for rice grown on a Cd polluted soil, the drain-out management can be adopted on soils with slight Cd pollution, and non-flooding management should avoided as possible. Use of Cd-resistant rice cultivars in combination with optimized nutrient and water management practices can produce rice product containing Cd below the permit levels by the state.
Tag Archive: Secondary
Effects of Different Sources of Secondary, Micro-and Beneficial Elements on Availability of Soil Cadmium and Its Uptake by Rice under Waterlogged Condition (Education Papers posted on January 23rd, 2015 )
Special Education Teachers’ Attitudes toward Coteaching (Education Papers posted on May 13th, 2014 )
Federal legislation mandates that students with disabilities have access to the generalcurriculum to the maximum extent possible. Coteaching provides a least restrictive environment for students with special needs in the general classroom as it allows them access to content at their level while providing opportunities to interact and learn from their peers in a manner condusive to their development. The purposes of this study were to: (a) design and pilot an instrument to measure, and then measure the attitudes of special education teachers toward the coteaching model； and (b) test if correlations exist between special education teachers’ attitudes toward coteaching and the key variables of years of coteaching experience, hours of collaboration with the coteacher, and time spent implementing students’ individual education plans. Vygotsky’s constructivist theory provided the framework for this descriptive and correlational study. Twenty-one special education teachers participated in this study by responding to the Teachers’ Attitude Scale toward Coteaching survey. Descriptive statisitcs indicated that special education teachers have mostly favorable attitudes toward coteaching and that teachers have concerns about their roles； Spearman’s rho results indicated that no statistically significant relationship exists between their attitudes and the other study variables. This study may provide school administrators and curriculum coordinators the foundation for developing an ongoing professional development program that focuses on providing teachers the necessary support and guidance needed to implement best practices in their cotaught environment.
Exploring principals’ perceptions of characteristics, practices, and programs that influence college readiness for low socioeconomic students in smaller Texas high schools: A Delphi study (Education Papers posted on May 13th, 2014 )
The purpose of this study was to investigate characteristics, practices, programs, and other factors of smaller Texas high schools that are successful at producing college-ready low-SES graduates. The analysis of the data provides insight into the characteristics, practices, programs, and other factors that influence college readiness for low-SES students. A Delphi panel of thirty-five high school principals participated in this study. The qualifying principals were leaders of Texas high schools with less than 1,000 students that had 50% or greater of the low-SES students classified as college-ready. Over the course of three rounds, the expert principals provided feedback to the researcher as to what characteristics, practices, programs, and other factors influence the college readiness for low SES-students. At the conclusion of round three, consensus was reached among the expert principals, and the data collection period was ended. The major findings of the study affirm that there are common characteristics and practices that increase the college readiness of low SES-students. The Delphi identified eight characteristics and five practices that all thirty-five expert principals felt influenced college readiness for low-SES students. The expert principals also provided comments to support the findings of this study.
Investigating mainstream teachers’ beliefs and experiences with English language learners (Education Papers posted on April 12th, 2014 )
Due to the rapidly evolving global demographics, the student population in Canada has become increasingly diverse, a transformation that has created extraordinary challenges for mainstream teachers with whom English language learners (ELLs) spend the majority of their instructional time. This qualitative study investigated mainstream teachers&rsquo； experiences, perceptions, and attitudes towards ELLs and the challenges associated with teaching ELLs. Through semi-structured interviews with 4 secondary school teachers, the study captured the situated experiences and stories of mainstream teachers who work with ELLs. While the findings indicate that most teachers have very positive attitudes and high levels of awareness of the learning needs of ELLs, the study also found that participants felt inadequately prepared to teach ELLs effectively in mainstream settings and that most teachers needed to move beyond the narrow perceptions of vocabulary as the only difficulty that ELLs experience to include the broader political, socio-cultural, and historical contexts of learning. This study could significantly add to our understanding of ELLs&rsquo； unique needs in mainstream classes and should be helpful to many educators, especially those who have an interest in instruction that is responsive to individuals and groups within our school system.
Understanding school dropout for teenage mothers with learning disabilities (Education Papers posted on March 27th, 2013 )
Educators have reported separate and extremely high dropout rates for youth with learning disabilities (LD) and teenage mothers. Although a dropout rate has not been reported for teenage mothers with LD, it is noteworthy that many young women who experience LD also become teenage mothers, and many young mothers with disabilities drop out of high school. Researchers have identified factors that are related to school dropout for youth in general, youth with LD, and teenage mothers. Yet, until the present dissertation study, there had not been an indepth investigation of the experiences that lead teenage mothers with LD who live in poverty in urban environments to drop out of school. In the present study, I built a theory of school dropout that was grounded in the experiences of 10 teenage mothers with LD who had dropped out of school and 10 teenage mothers with LD who had never dropped out. I found that network support, school support, and motivation were critical to school persistence. In general, I also found that a lack of support, together with other priorities, eroded the motivation for school of teenage mothers with LD. After dropping out, the teenage mothers with LD reported feeling unhappy about their dropout status and developing motivation for school. As a result, all of the teenage mothers who dropped out engaged in strategies to re-enroll and sustain their reenrollment in some type of secondary educational setting. The teenage mothers who were successful at sustaining their re-enrollment in secondaryprograms were those who were able to compensate for the lack of network and school supports that had led them to drop out of school. These results have important implications for future research on the school experiences of teenage mothers with LD. In addition, the study findings have important implications for designing interventions to prevent school dropout and to promote school retention and recovery of teenage mothers with LD.
The technical adequacy of curriculum-based measurement in writing with English language learners (Education Papers posted on March 26th, 2013 )
The purpose of this study was to examine the validity and reliability of writing measures that could be used to indicate general writing proficiency among English language learners. Participants were 57 students in three high school ESL classes. Students in ESL 1-2 had the lowest English proficiency n ＝ 21)； students in ESL 3 had moderate English proficiency n ＝ 17), and students in ESL 4-5 had higher English proficiency n ＝ 19). Predictor variables were passage-copying and free-writing. For passage-copying, students copied Hard and Easy passages. For free-writing, students wrote in response to a prompt. Three types of prompts, Picture, Narrative, and Expository, were used. Free-writing was found to be more reliable and valid than passage-copying. Alternate-form reliabilities for passage-copying were generally in the moderate range, while free-writing produced moderate to strong alternate-form reliabilities. Observed validity coefficients were also stronger for the free-writing than for the passage-copying tasks. Ultimately, 5 or 7 minutes of writing in response to Narrative prompts, scored for %CWS or CMIWS, were found to be the most promising measures for determining ELL writing English performance. Both passage-copying tasks and free-writing tasks differentiated between low proficiency and high proficiency students. Easy copying scored for CWS or CMIWS discriminated between ESL 1-2 and ESL 4-5 as well as ESL 3 and ESL 4-5, but did not discriminate between the lower levels of ESL 1-2 and ESL 3. Scoring %CWS and CMIWS for 5 and 7 minutes of writing in response to a Narrative prompt discriminated between ESL 3 and ESL 4-5 students.
Negotiating between subject area and student: The devolution and evolution of language arts traditions in Hawaiian-based education (Education Papers posted on March 26th, 2013 )
This dissertation researched how sixth, seventh, and eighth grade language arts teachers in a Hawaiian language immersion school and a Hawaiian public charter school culturally negotiate their students’ contrastingand educational worlds (the indigenous and mainstream Euro Western) through specific culturally based language arts teaching practices. In the first phase of the study, grounded theory design was used to compare common practices across the sites and determine where and how these practices intersected two differing educational frameworks—the language arts state standards and the Hawai’i Guidelines for Culturally Healthy and Responsive Learning Environments (also known as Na Honua Mauli Ola), which is specific to Hawaiian-based . Teaching practices that were found to intersect the two educational frameworks were characterized as “culturally negotiated” language arts teaching practices and contextualized further during the second phase of the study, consisting of case study analyses of four teacher-participants. Five significant culturally negotiated commonalities in content, methodology, and ideology surfaced throughout the study, each characterizing the actualization of culturally negotiated language arts teaching: (1) the relationship with the “traditional” uses of and the attitude toward language, (2) the understanding and incorporation of mo’olelo [Hawaiian myth], (3) the creative means of language expression； (4) the “family” environment of the class and the connection to community, and (5) the physical learning environment in which learning takes place. These findings are presented in terms of the learning benefits for Native Hawaiian students and the innovative and necessary evolution of language arts teaching.
A study of literacy efficacy and student achievement among beginning middle school teachers in an urban context (Education Papers posted on March 25th, 2013 )
Many U.S. school districts are addressing concerns in the areas of literacy, teacher shortages, and overall student achievement. Teacher preparation in the area of literacy and the ability of core subject teachers to include literacy components in their daily lessons appears vital to student achievement. Teacher shortages, particularly in high need, “hard to staff urban schools, are a serious problem that alternative preparation programs help to address. Alternative preparation programs can provide highly qualified teachers in urban schools. The Transition to Teaching TTT) trained teachers provided literacy that in turn helped improve benchmark tests, end-of-year tests, cumulative scores, and standardized test scores. The TTT Program, a joint partnership between a southeastern Virginia urban school system and a local four-year public university, provides a viable solution which addresses the need for highly qualified core teachers with literacy training in the school division. A quasi-experimental design was used to compare achievement levels of students taught by beginning core-area teachers prepared with content-specific coursework for teaching literacy skills in the TTT school-university partnership program with students taught by beginning core-area teachers who did not experience content-specific coursework for teaching literacy skills. The two groups of teachers, TTT and non-TTT, were also measured on literacy teaching efficacy based on scores from a literacy survey instrument. Results from the study in the area of student achievement revealed that middle school students taught by the beginning TTT teachers trained with content-specific coursework in teaching literacy skills achieved better overall than those students taught by the beginning non-TTT teachers who had no specific training in teaching literacy skills. Results from the literacy survey revealed no significant differences between TTT and non-TTT teachers in overall literacy teaching efficacy and their beliefs about the importance of teaching literacy skills across the curriculum. In summary, the study showed that the experience of completing content-specific coursework in teaching literacy skills positively impacted student achievement in middle school core academic content areas.
The development of a professional learning community: One high school’s experience (Education Papers posted on March 24th, 2013 )
The purpose of this study was to examine whether, and how, a group of Nooksack Valley High School teachers developed as a professional learning community through participation in a nine month action research project focused on understanding and improving student motivation and engagement. The specific research question that framed this study was； In what ways, if any, does a professional learning community develop among a group of teachers and administrators engaged in a jointly constructed action research project focused on increasing their high school students motivation and engagement in learning? This study served as an opportunity to learn about how and why professional learning community develops in a high school that appeared to be challenged with creating such communities of adult learners, focused on teaching and learning. The study used a literature based, preconceived professional learning community conceptual framework as a lens through which to conduct the analysis. The framework outlines five key elements and corresponding operational indicators. The study found that this team did develop as a professional learning community, and suggested three main categories as important factors in this development. These included leadership roles and decisions, the establishment of specific content for the action research team to learn, and common processes through which the team could learn and apply the content.
Perception of the future need for family and consumer sciences teachers in North Dakota’s public schools (Education Papers posted on March 23rd, 2013 )
Family and consumer sciences FACS) school programs provide some of the earliest opportunities for students to learn relationship, communications, teamwork, and decision-making skills that support and strengthen family life and to make healthy lifestyle choices that have a positive impact on all of society. Unfortunately, research data document a shortage of FACS teachers across the nation. Without an increasing supply of teachers, many programs may be weakened and some may be eliminated. The purpose of this study is to identify the future need for FACS teachers in the North Dakota public schools. A secondary purpose is to identify the reasons why FACS middle and secondary programs are closing and what North Dakota could do to stop this trend. A survey was sent to 185 FACS teachers in North Dakota public schools and to 147 of their principals. Completion and return rates for FACS teachers were 157 surveys 85%) and the principals were 77 surveys 52%). Frequency distribution and percentages was computed on the teachers and principals personal and teaching or administrative data, career plans, and their beliefs about the future of FACS as a teaching profession. Total means were computed for the sections using the five-point Likert-type scales for each time period next year, five years, and ten years) and for both the teachers and principals surveys. A t-test was used to determine if there was a significant difference between the FACS teachers verses the principals beliefs about the future of FACS as a teaching profession. The FACS teacher crisis will happen in the next five years and steadily continue for ten years. Retirements will decrease the supply, thus not meeting the need of middle and secondary programs. North Dakota State University FACSgraduates will not keep up with the retirements. The reason why FACS middle and secondary programs are closing is because of the lack of qualified teachers. The solution: Encouraging 7-8th graders to acquire additional life and occupational skills from high school FACS classes and to pursue a FACS teaching career by updating the curriculum and image of both the FACS teacher and the program.