Health hazards of ultrafine metal and metal oxide powders

Study reveals that suggested threshold limit values are from two to fifty times lower than current recommended threshold limit values. Proposed safe limits of exposure to the ultrafine dusts are based on known toxic potential of various materials as determined in particle size ranges

Energy input is primary controller of methane bubbling in subarctic lakes

Emission of methane (CH4) from surface waters is often dominated by ebullition (bubbling), a transport mode with high‐spatiotemporal variability. Based on new and extensive CH4 ebullition data, we demonstrate striking correlations (r2 between 0.92 and 0.997) when comparing seasonal bubble CH4 flux from three shallow subarctic lakes to four readily measurable proxies of incoming energy flux and daily flux magnitudes to surface sediment temperature (r2 between 0.86 and 0.94). Our results after continuous multiyear sampling suggest that CH4 ebullition is a predictable process, and that heat flux into the lakes is the dominant driver of gas production and release. Future changes in the energy received by lakes and ponds due to shorter ice‐covered seasons will predictably alter the ebullitive CH4 flux from freshwater systems across northern landscapes. This finding is critical for our understanding of the dynamics of radiatively important trace gas sources and associated climate feedback

The State as Mujahid: Jihadist Norms in International Narrative of Saudi Arabia

This study explored Saudi narrative for the expression of jihadist norms and tested the extent to which Critical Constructivism can account for the presence (or absence) of those norms. Rather than identifying jihadist norms, this study found that contra-norms are expressed in Saudi narrative. These are expressed in a complex way, preserving the legitimacy of Saudi Arabia in multiple theatres. Further, it found Critical Constructivism is sufficient to explain the presence of these norms given the various power dynamics

Effects of acidification on the primary producers of softwater lakes

Published in Acid Deposition, Donald D. Adams, ed. Plenum Publishing, 1985, p. 163-18

Investigating Student and Teacher Perspectives on Approaches Toward Student Epistemic Agency Through a Socioscientific Issue in Secondary Science Classrooms

Purpose of the Study: This research study hopes to address the negotiation of important aspects in teaching such as how to foster inquiry and literacy while adhering to standards, specifically the Next Generation Science Standards, and if those standards allow for student epistemic agency in secondary science classrooms. The future of science education lies in teachers instilling in their students the skills that will help them gain scientific literacy and student agency in the classroom, and beyond. For the purposes of this study, a framework was developed around scientific inquiry and literacy, while negotiating varying pedagogical approaches, along a theorized spectrum of increasing student agency. The framework is a tool to help educators visualize a variety of pedagogies as they relate to important characteristics of stages of inquiry that could offer increasing epistemic agency for their students. This research study intends to shed light on the perspectives and opinions of a selected group of high school life science teachers and some of their students in regards to these approaches to teaching a controversial, or Socioscientific Issue (SSI), in the science classroom. The student outcome goals that were considered were critical thinking, personal decision making, ethical questioning, outreach and “social justice” as activism. The three classrooms include one Sheltered Learning biology class and one Advanced Placement biology, both at the same high school, and one Integrated 3-4 biology class in a neighboring County. Within and across the three different classrooms, how do participating teachers, and their students’ perceive, or view, (a) varying approaches toward using a controversial, or Socioscientific Issue (SSI), such as GMOs, in secondary science classroom, and (b) activities designed for the science classroom that have the end goals of outreach, social justice or activism, on or off campus? Finally, how does student preference compare to the proposed theoretical framework set forth in this study? Procedure: This mixed-method study is a one-phase embedded design approach; where quantitative data is the secondary data that was collected while qualitative data was being audio recorded during teacher and student interviews. Four activity “scenarios” were designed, along with interview questionnaires, and used as tools and guides during teacher and student interviews. Three high school life science teachers and 13 of their students were interviewed to investigate their perspectives on using the four different activity scenarios which would explore the topic of genetically modified organisms (GMOs) as food. Quantitative and qualitative data were collected and analyzed. Findings: Overall, two classes preferred Activity 1; critical thinking in the lab, whereas one classroom preferred Activities 3; outreach and 4; activism, although students had a variety of responses as to why. All three teachers and many students agreed that outreach and activism are important. However, teachers believed that activities that stayed in the classroom were more feasible that activities that left the classroom. Teachers were fairly accurate when predicting their students preferred activity scenario. All the participants said that GMOs as food would be a good topic for learning science in the classroom. Teachers and students felt that activities that are controversial, or that might cause conflict in the classroom, are acceptable for learning at school. Those who were asked felt that conflict can be managed and usually does not leave the classroom. When the varying perspectives within classrooms were reflected on the spectrum, new ideas about what student epistemic agency and scientific literacy are emerged. Conclusions: Student epistemic agency can be defined in many ways, including what the students want to do most. However, agency through varying teaching approaches and a variety of student outcome goals can bring different forms of agency to students while doing inquiry in the science classroom. Finally, students may come into the classroom with prior experiences that give them a different “position” when negotiating a controversial, or socioscientific, type issue. Implications for teaching practice involve balancing factors that are within our control, such as activity planning and pedagogical approach, with factors that are out of teachers control, such as the starting point of a student’s position when they enter the classroom for learning. This starting point position can have large impacts on a student’s perceptions, and willingness, to “like” activities Finally, teachers play a large role in how learning can happen in the classroom, as well the school and society that they lie within.Boylen, Sarah C. 2020. Investigating Student and Teacher Perspectives on Approaches toward Student Epistemic Agency through a Socioscientific Issue in Secondary Science Classrooms. Department of Education, Sonoma State University

Prediction of uncomplicated pregnancies in obese women: A prospective multicentre study

BACKGROUND: All obese pregnant women are considered at equal high risk with respect to complications in pregnancy and birth, and are commonly managed through resource-intensive care pathways. However, the identification of maternal characteristics associated with normal pregnancy outcomes could assist in the management of these pregnancies. The present study aims to identify the factors associated with uncomplicated pregnancy and birth in obese women, and to assess their predictive performance. METHODS: Data form obese women (BMI ≥ 30 kg/m 2 ) with singleton pregnancies included in the UPBEAT trial were used in this analysis. Multivariable logistic regression was used to identify sociodemographic, clinical and biochemical factors at 15 +0 to 18 +6 weeks' gestation associated with uncomplicated pregnancy and birth, defined as delivery of a term live-born infant without antenatal or labour complications. Predictive performance was assessed using area under the receiver operating characteristic curve (AUROC). Internal validation and calibration were also performed. Women were divided into fifths of risk and pregnancy outcomes were compared between groups. Sensitivity, specificity, and positive and negative predictive values were calculated using the upper fifth as the positive screening group. RESULTS: Amongst 1409 participants (BMI 36.4, SD 4.8 kg/m 2 ), the prevalence of uncomplicated pregnancy and birth was 36% (505/1409). Multiparity and increased plasma adiponectin, maternal age, systolic blood pressure and HbA1c were independently associated with uncomplicated pregnancy and birth. These factors achieved an AUROC of 0.72 (0.68-0.76) and the model was well calibrated. Prevalence of gestational diabetes, preeclampsia and other hypertensive disorders, preterm birth, and postpartum haemorrhage decreased whereas spontaneous vaginal delivery increased across the fifths of increasing predicted risk of uncomplicated pregnancy and birth. Sensitivity, specificity, and positive and negative predictive values were 38%, 89%, 63% and 74%, respectively. A simpler model including clinical factors only (no biomarkers) achieved an AUROC of 0.68 (0.65-0.71), with sensitivity, specificity, and positive and negative predictive values of 31%, 86%, 56% and 69%, respectively. CONCLUSION: Clinical factors and biomarkers can be used to help stratify pregnancy and delivery risk amongst obese pregnant women. Further studies are needed to explore alternative pathways of care for obese women demonstrating different risk profiles for uncomplicated pregnancy and birth

Effect of restrictive temperature on cell wall synthesis in a temperature-sensitive mutant of Bacillus stearothermophilus

Published in the Journal of Bacteriology, Oct. 1980, vol. 144, no. 1, p. 413-42